<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:57758278-b97d-4d1b-8489-3bae795982ef,g:323577b1-67e1-4885-a3f3-90102e643701-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://www.ftandi.com/role/CONSOLIDATEDBALANCESHEETS" xlink:type="simple" xlink:href="fip-20260331.xsd#CONSOLIDATEDBALANCESHEETS"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/CONSOLIDATEDBALANCESHEETS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_1edc2f63-2059-43d8-b07e-21a5dec2fa58" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_76f6ae15-b2c0-4a02-b9db-0390b23963d3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_1edc2f63-2059-43d8-b07e-21a5dec2fa58" xlink:to="loc_us-gaap_StatementTable_76f6ae15-b2c0-4a02-b9db-0390b23963d3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_e62ccd5f-bc03-46ea-95eb-417aa9cdb19e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_76f6ae15-b2c0-4a02-b9db-0390b23963d3" xlink:to="loc_us-gaap_StatementClassOfStockAxis_e62ccd5f-bc03-46ea-95eb-417aa9cdb19e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_e62ccd5f-bc03-46ea-95eb-417aa9cdb19e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_e62ccd5f-bc03-46ea-95eb-417aa9cdb19e" xlink:to="loc_us-gaap_ClassOfStockDomain_e62ccd5f-bc03-46ea-95eb-417aa9cdb19e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_11aaa02e-fa73-4f77-b43b-df2527a11f8f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_e62ccd5f-bc03-46ea-95eb-417aa9cdb19e" xlink:to="loc_us-gaap_ClassOfStockDomain_11aaa02e-fa73-4f77-b43b-df2527a11f8f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesBPreferredStockMember_46197fda-1ea9-4708-abdc-24749f3d6753" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesBPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_11aaa02e-fa73-4f77-b43b-df2527a11f8f" xlink:to="loc_us-gaap_SeriesBPreferredStockMember_46197fda-1ea9-4708-abdc-24749f3d6753" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_SeriesAPreferredStockRailcoMember_2454b591-1f73-4ba0-88f7-a136efc01049" xlink:href="fip-20260331.xsd#fip_SeriesAPreferredStockRailcoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_11aaa02e-fa73-4f77-b43b-df2527a11f8f" xlink:to="loc_fip_SeriesAPreferredStockRailcoMember_2454b591-1f73-4ba0-88f7-a136efc01049" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract_a4c94201-24b6-4025-acc7-9afd432628bb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_1edc2f63-2059-43d8-b07e-21a5dec2fa58" xlink:to="loc_us-gaap_AssetsAbstract_a4c94201-24b6-4025-acc7-9afd432628bb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrentAbstract_0df55e0f-e589-49fa-a3ab-b36d7a338e2d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_a4c94201-24b6-4025-acc7-9afd432628bb" xlink:to="loc_us-gaap_AssetsCurrentAbstract_0df55e0f-e589-49fa-a3ab-b36d7a338e2d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_ddb9c94b-d601-45bc-ab74-546aa6d58adb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_0df55e0f-e589-49fa-a3ab-b36d7a338e2d" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_ddb9c94b-d601-45bc-ab74-546aa6d58adb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalents_907a2b5c-64e1-4105-9a2f-768b418c1059" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashAndCashEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_0df55e0f-e589-49fa-a3ab-b36d7a338e2d" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalents_907a2b5c-64e1-4105-9a2f-768b418c1059" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesReceivableNet_1e3fedc4-f17a-4163-8392-89043e079ad1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesReceivableNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_0df55e0f-e589-49fa-a3ab-b36d7a338e2d" xlink:to="loc_us-gaap_NotesReceivableNet_1e3fedc4-f17a-4163-8392-89043e079ad1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsCurrent_c89daf3c-93a3-4ea3-8abe-c8d9d10ed8b2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_0df55e0f-e589-49fa-a3ab-b36d7a338e2d" xlink:to="loc_us-gaap_OtherAssetsCurrent_c89daf3c-93a3-4ea3-8abe-c8d9d10ed8b2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_cc1be5fb-19ad-47d3-a0b1-135c3d090ca9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_0df55e0f-e589-49fa-a3ab-b36d7a338e2d" xlink:to="loc_us-gaap_AssetsCurrent_cc1be5fb-19ad-47d3-a0b1-135c3d090ca9" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_PropertyPlantAndEquipmentLeasingEquipment_995d368d-a320-4c89-bee3-e89ac65771a5" xlink:href="fip-20260331.xsd#fip_PropertyPlantAndEquipmentLeasingEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_a4c94201-24b6-4025-acc7-9afd432628bb" xlink:to="loc_fip_PropertyPlantAndEquipmentLeasingEquipment_995d368d-a320-4c89-bee3-e89ac65771a5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_864eef15-f99a-47af-84e9-9267e0b04b7a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_a4c94201-24b6-4025-acc7-9afd432628bb" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_864eef15-f99a-47af-84e9-9267e0b04b7a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_8649b724-68b9-49e3-a73d-461eda9b0e14" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_a4c94201-24b6-4025-acc7-9afd432628bb" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_8649b724-68b9-49e3-a73d-461eda9b0e14" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_EquityMethodInvestmentIncludingAvailableForSaleSecurities_c7c5f6dd-a557-4825-b711-72cfa5382aa6" xlink:href="fip-20260331.xsd#fip_EquityMethodInvestmentIncludingAvailableForSaleSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_a4c94201-24b6-4025-acc7-9afd432628bb" xlink:to="loc_fip_EquityMethodInvestmentIncludingAvailableForSaleSecurities_c7c5f6dd-a557-4825-b711-72cfa5382aa6" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_71609750-4e37-484a-b2b4-3df4644e00a5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_a4c94201-24b6-4025-acc7-9afd432628bb" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_71609750-4e37-484a-b2b4-3df4644e00a5" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_c4563956-299d-4764-bba5-be3315f37634" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_a4c94201-24b6-4025-acc7-9afd432628bb" xlink:to="loc_us-gaap_Goodwill_c4563956-299d-4764-bba5-be3315f37634" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_869114e7-d29e-40d1-a3d1-3d3d35cb026b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_a4c94201-24b6-4025-acc7-9afd432628bb" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_869114e7-d29e-40d1-a3d1-3d3d35cb026b" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_f2c29096-efa3-4ba3-87c4-7227229ce512" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_a4c94201-24b6-4025-acc7-9afd432628bb" xlink:to="loc_us-gaap_Assets_f2c29096-efa3-4ba3-87c4-7227229ce512" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAbstract_bde2b4f3-bc34-462e-8ae6-0cd0eb136192" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_1edc2f63-2059-43d8-b07e-21a5dec2fa58" xlink:to="loc_us-gaap_LiabilitiesAbstract_bde2b4f3-bc34-462e-8ae6-0cd0eb136192" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract_ba664aed-4fa3-4913-9c8d-5892b2069c3f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_bde2b4f3-bc34-462e-8ae6-0cd0eb136192" xlink:to="loc_us-gaap_LiabilitiesCurrentAbstract_ba664aed-4fa3-4913-9c8d-5892b2069c3f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent_661a3faa-8754-4978-a2bd-9da4639a70ac" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_ba664aed-4fa3-4913-9c8d-5892b2069c3f" xlink:to="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent_661a3faa-8754-4978-a2bd-9da4639a70ac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtCurrent_535cd8b8-b1a1-4648-867f-7ec963217b6f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_ba664aed-4fa3-4913-9c8d-5892b2069c3f" xlink:to="loc_us-gaap_DebtCurrent_535cd8b8-b1a1-4648-867f-7ec963217b6f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityCurrent_6f6891c4-45f6-4180-9863-5895fecc79d2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_ba664aed-4fa3-4913-9c8d-5892b2069c3f" xlink:to="loc_us-gaap_OperatingLeaseLiabilityCurrent_6f6891c4-45f6-4180-9863-5895fecc79d2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilitiesCurrent_1fe0d588-2580-409c-8463-7f54d38d67ff" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_ba664aed-4fa3-4913-9c8d-5892b2069c3f" xlink:to="loc_us-gaap_DerivativeLiabilitiesCurrent_1fe0d588-2580-409c-8463-7f54d38d67ff" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesCurrent_7c8fba2c-3101-46d8-b7f6-792a8245421a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_ba664aed-4fa3-4913-9c8d-5892b2069c3f" xlink:to="loc_us-gaap_OtherLiabilitiesCurrent_7c8fba2c-3101-46d8-b7f6-792a8245421a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_8d12bef3-3930-48ba-9c83-c3a627aa8432" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_ba664aed-4fa3-4913-9c8d-5892b2069c3f" xlink:to="loc_us-gaap_LiabilitiesCurrent_8d12bef3-3930-48ba-9c83-c3a627aa8432" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_95f7ce9e-9cde-4c8c-9e09-12f83d930f01" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_bde2b4f3-bc34-462e-8ae6-0cd0eb136192" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_95f7ce9e-9cde-4c8c-9e09-12f83d930f01" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_efd6f64a-f457-4428-80c7-ecb48a4fd99f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_bde2b4f3-bc34-462e-8ae6-0cd0eb136192" xlink:to="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_efd6f64a-f457-4428-80c7-ecb48a4fd99f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxesAndOtherTaxLiabilitiesNoncurrent_019cbf96-7cb5-79ac-b665-99bef7edbcbd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxesAndOtherTaxLiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_bde2b4f3-bc34-462e-8ae6-0cd0eb136192" xlink:to="loc_us-gaap_DeferredIncomeTaxesAndOtherTaxLiabilitiesNoncurrent_019cbf96-7cb5-79ac-b665-99bef7edbcbd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilitiesNoncurrent_7461dd3a-fa6c-4727-af42-63954dc8b9c7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_bde2b4f3-bc34-462e-8ae6-0cd0eb136192" xlink:to="loc_us-gaap_DerivativeLiabilitiesNoncurrent_7461dd3a-fa6c-4727-af42-63954dc8b9c7" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_WarrantLiabilityNoncurrent_a5de75e1-e2a1-446c-a8fe-24806a0a6c18" xlink:href="fip-20260331.xsd#fip_WarrantLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_bde2b4f3-bc34-462e-8ae6-0cd0eb136192" xlink:to="loc_fip_WarrantLiabilityNoncurrent_a5de75e1-e2a1-446c-a8fe-24806a0a6c18" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilities_5851ddee-0319-4834-acdb-9e93f525dc48" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_bde2b4f3-bc34-462e-8ae6-0cd0eb136192" xlink:to="loc_us-gaap_OtherLiabilities_5851ddee-0319-4834-acdb-9e93f525dc48" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_bd338021-9b29-4e1d-a355-87198e52e6df" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Liabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_bde2b4f3-bc34-462e-8ae6-0cd0eb136192" xlink:to="loc_us-gaap_Liabilities_bd338021-9b29-4e1d-a355-87198e52e6df" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies_6702f1df-50ff-4621-97e4-dbc486e39acf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommitmentsAndContingencies"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_1edc2f63-2059-43d8-b07e-21a5dec2fa58" xlink:to="loc_us-gaap_CommitmentsAndContingencies_6702f1df-50ff-4621-97e4-dbc486e39acf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityCarryingAmountAttributableToParent_7badfc53-7f33-4dc8-a36b-e655ee17f4e1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquityCarryingAmountAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_1edc2f63-2059-43d8-b07e-21a5dec2fa58" xlink:to="loc_us-gaap_TemporaryEquityCarryingAmountAttributableToParent_7badfc53-7f33-4dc8-a36b-e655ee17f4e1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MembersEquityAbstract_5fb72324-3f56-43c8-a9d7-a5da61323d7b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MembersEquityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_1edc2f63-2059-43d8-b07e-21a5dec2fa58" xlink:to="loc_us-gaap_MembersEquityAbstract_5fb72324-3f56-43c8-a9d7-a5da61323d7b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_2f30b849-211c-4b48-bded-42bfafda59e2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MembersEquityAbstract_5fb72324-3f56-43c8-a9d7-a5da61323d7b" xlink:to="loc_us-gaap_CommonStockValue_2f30b849-211c-4b48-bded-42bfafda59e2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapital_0b0d7c98-d68a-47a1-88fa-10af1a4dcdd7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdditionalPaidInCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MembersEquityAbstract_5fb72324-3f56-43c8-a9d7-a5da61323d7b" xlink:to="loc_us-gaap_AdditionalPaidInCapital_0b0d7c98-d68a-47a1-88fa-10af1a4dcdd7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_931589db-86ac-4b7b-a2bc-ef99873fd91a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MembersEquityAbstract_5fb72324-3f56-43c8-a9d7-a5da61323d7b" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_931589db-86ac-4b7b-a2bc-ef99873fd91a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_0645233b-c063-4ae6-bc4e-c734c21db26e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MembersEquityAbstract_5fb72324-3f56-43c8-a9d7-a5da61323d7b" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_0645233b-c063-4ae6-bc4e-c734c21db26e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_2ebaf5ac-e68e-486a-88c3-98a3cf8b7b13" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MembersEquityAbstract_5fb72324-3f56-43c8-a9d7-a5da61323d7b" xlink:to="loc_us-gaap_StockholdersEquity_2ebaf5ac-e68e-486a-88c3-98a3cf8b7b13" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterest_360955c7-82e1-498c-b819-cde3ae7f64c5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MinorityInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MembersEquityAbstract_5fb72324-3f56-43c8-a9d7-a5da61323d7b" xlink:to="loc_us-gaap_MinorityInterest_360955c7-82e1-498c-b819-cde3ae7f64c5" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_52c394aa-a86f-447a-a987-663ae5bc7175" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MembersEquityAbstract_5fb72324-3f56-43c8-a9d7-a5da61323d7b" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_52c394aa-a86f-447a-a987-663ae5bc7175" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_327965ae-352f-44be-9c2d-554924295e09" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_1edc2f63-2059-43d8-b07e-21a5dec2fa58" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_327965ae-352f-44be-9c2d-554924295e09" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/CONSOLIDATEDBALANCESHEETSParenthetical" xlink:type="simple" xlink:href="fip-20260331.xsd#CONSOLIDATEDBALANCESHEETSParenthetical"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/CONSOLIDATEDBALANCESHEETSParenthetical" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_196ffa88-e461-4ee9-b679-1eb258238fcd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_1e3c96b0-d482-4280-8a29-6f6ae69f33c8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_196ffa88-e461-4ee9-b679-1eb258238fcd" xlink:to="loc_us-gaap_StatementTable_1e3c96b0-d482-4280-8a29-6f6ae69f33c8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_977cbfaf-7345-45d6-aa3f-12faa263e605" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_1e3c96b0-d482-4280-8a29-6f6ae69f33c8" xlink:to="loc_us-gaap_StatementClassOfStockAxis_977cbfaf-7345-45d6-aa3f-12faa263e605" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_977cbfaf-7345-45d6-aa3f-12faa263e605_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_977cbfaf-7345-45d6-aa3f-12faa263e605" xlink:to="loc_us-gaap_ClassOfStockDomain_977cbfaf-7345-45d6-aa3f-12faa263e605_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_eeec3595-ad20-4f73-9405-c906f005bd8c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_977cbfaf-7345-45d6-aa3f-12faa263e605" xlink:to="loc_us-gaap_ClassOfStockDomain_eeec3595-ad20-4f73-9405-c906f005bd8c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesBPreferredStockMember_0cbe165a-8932-4a25-aee7-35f3968e40aa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesBPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_eeec3595-ad20-4f73-9405-c906f005bd8c" xlink:to="loc_us-gaap_SeriesBPreferredStockMember_0cbe165a-8932-4a25-aee7-35f3968e40aa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_SeriesAPreferredStockRailcoMember_94d7b119-2e83-433c-b933-af6ae459e7f9" xlink:href="fip-20260331.xsd#fip_SeriesAPreferredStockRailcoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_eeec3595-ad20-4f73-9405-c906f005bd8c" xlink:to="loc_fip_SeriesAPreferredStockRailcoMember_94d7b119-2e83-433c-b933-af6ae459e7f9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquitySharesIssued_40470ec0-ec12-4501-ac44-9df1a1612ecd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquitySharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_196ffa88-e461-4ee9-b679-1eb258238fcd" xlink:to="loc_us-gaap_TemporaryEquitySharesIssued_40470ec0-ec12-4501-ac44-9df1a1612ecd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityParOrStatedValuePerShare_eff72e12-d38f-4364-b2e5-624b4d52c721" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquityParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_196ffa88-e461-4ee9-b679-1eb258238fcd" xlink:to="loc_us-gaap_TemporaryEquityParOrStatedValuePerShare_eff72e12-d38f-4364-b2e5-624b4d52c721" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquitySharesAuthorized_4b75547e-b706-4b59-904a-8e5f8a60a411" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquitySharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_196ffa88-e461-4ee9-b679-1eb258238fcd" xlink:to="loc_us-gaap_TemporaryEquitySharesAuthorized_4b75547e-b706-4b59-904a-8e5f8a60a411" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquitySharesIssued_66bc8dbe-f31c-434c-8703-122387a525ff" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquitySharesIssued"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquitySharesOutstanding_058a31e4-b35e-43ec-87fe-891fbc595987" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquitySharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_196ffa88-e461-4ee9-b679-1eb258238fcd" xlink:to="loc_us-gaap_TemporaryEquitySharesOutstanding_058a31e4-b35e-43ec-87fe-891fbc595987" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityLiquidationPreference_f9106712-985b-4bea-99d6-43006645f950" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquityLiquidationPreference"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_196ffa88-e461-4ee9-b679-1eb258238fcd" xlink:to="loc_us-gaap_TemporaryEquityLiquidationPreference_f9106712-985b-4bea-99d6-43006645f950" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_a8a58991-44d2-4e66-a588-605791c47974" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_196ffa88-e461-4ee9-b679-1eb258238fcd" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_a8a58991-44d2-4e66-a588-605791c47974" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_53a759ed-0b53-4ef8-92be-a5044fb78354" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_196ffa88-e461-4ee9-b679-1eb258238fcd" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_53a759ed-0b53-4ef8-92be-a5044fb78354" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_fd7df52b-17e6-4e9f-9ad6-9d938abce50c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_196ffa88-e461-4ee9-b679-1eb258238fcd" xlink:to="loc_us-gaap_CommonStockSharesIssued_fd7df52b-17e6-4e9f-9ad6-9d938abce50c" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_ac4e19cf-1fc2-4a69-bd8b-ed865016af6b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_196ffa88-e461-4ee9-b679-1eb258238fcd" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_ac4e19cf-1fc2-4a69-bd8b-ed865016af6b" xlink:type="arc" order="9"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/CONSOLIDATEDANDCOMBINEDCONSOLIDATEDSTATEMENTOFCHANGESINEQUITYunaudited" xlink:type="simple" xlink:href="fip-20260331.xsd#CONSOLIDATEDANDCOMBINEDCONSOLIDATEDSTATEMENTOFCHANGESINEQUITYunaudited"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/CONSOLIDATEDANDCOMBINEDCONSOLIDATEDSTATEMENTOFCHANGESINEQUITYunaudited" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_6c2cd128-e0ba-4fa0-ad29-15f4c21db258" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_ca9f3af4-e246-4638-a891-7b9b1e4c4207" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_6c2cd128-e0ba-4fa0-ad29-15f4c21db258" xlink:to="loc_us-gaap_StatementTable_ca9f3af4-e246-4638-a891-7b9b1e4c4207" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_b1feeec8-e278-4a23-b252-2087242d011a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_ca9f3af4-e246-4638-a891-7b9b1e4c4207" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_b1feeec8-e278-4a23-b252-2087242d011a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_b1feeec8-e278-4a23-b252-2087242d011a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_b1feeec8-e278-4a23-b252-2087242d011a" xlink:to="loc_us-gaap_EquityComponentDomain_b1feeec8-e278-4a23-b252-2087242d011a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_16549e41-bc08-4f12-8ff7-3d9d85001f84" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_b1feeec8-e278-4a23-b252-2087242d011a" xlink:to="loc_us-gaap_EquityComponentDomain_16549e41-bc08-4f12-8ff7-3d9d85001f84" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_40043330-b96e-4651-90ac-4f093b19122c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_16549e41-bc08-4f12-8ff7-3d9d85001f84" xlink:to="loc_us-gaap_CommonStockMember_40043330-b96e-4651-90ac-4f093b19122c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_ffeb88d6-5c55-44c9-8db4-cc6ae544a99f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_16549e41-bc08-4f12-8ff7-3d9d85001f84" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_ffeb88d6-5c55-44c9-8db4-cc6ae544a99f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_34f157eb-d7a9-4121-a5e2-6c49044cb341" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_16549e41-bc08-4f12-8ff7-3d9d85001f84" xlink:to="loc_us-gaap_RetainedEarningsMember_34f157eb-d7a9-4121-a5e2-6c49044cb341" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_d9ce154e-2058-4127-aaa3-0a2c222fdb9b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_16549e41-bc08-4f12-8ff7-3d9d85001f84" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_d9ce154e-2058-4127-aaa3-0a2c222fdb9b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestMember_cbd9c71b-2df9-4ee6-aebb-8dc718bab435" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_16549e41-bc08-4f12-8ff7-3d9d85001f84" xlink:to="loc_us-gaap_NoncontrollingInterestMember_cbd9c71b-2df9-4ee6-aebb-8dc718bab435" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_1409a828-05a7-45b4-906d-3a500ecb9c80" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_ca9f3af4-e246-4638-a891-7b9b1e4c4207" xlink:to="loc_us-gaap_StatementClassOfStockAxis_1409a828-05a7-45b4-906d-3a500ecb9c80" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_1409a828-05a7-45b4-906d-3a500ecb9c80_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_1409a828-05a7-45b4-906d-3a500ecb9c80" xlink:to="loc_us-gaap_ClassOfStockDomain_1409a828-05a7-45b4-906d-3a500ecb9c80_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_ebbadd86-b142-484f-90f4-badd4ec31837" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_1409a828-05a7-45b4-906d-3a500ecb9c80" xlink:to="loc_us-gaap_ClassOfStockDomain_ebbadd86-b142-484f-90f4-badd4ec31837" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_56f33ad3-2ef1-4b00-a234-3be3c4a2a0bd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_ebbadd86-b142-484f-90f4-badd4ec31837" xlink:to="loc_us-gaap_CommonStockMember_56f33ad3-2ef1-4b00-a234-3be3c4a2a0bd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_2ab0a426-40f7-4e4a-86e3-c4fd1932aba4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInPartnersCapitalRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6c2cd128-e0ba-4fa0-ad29-15f4c21db258" xlink:to="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_2ab0a426-40f7-4e4a-86e3-c4fd1932aba4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_ba5f21ac-31e8-44e4-93bf-7fdffb7d1956" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_2ab0a426-40f7-4e4a-86e3-c4fd1932aba4" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_ba5f21ac-31e8-44e4-93bf-7fdffb7d1956" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_27d4b657-0fe2-44ba-a49e-3c55065cf98f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_2ab0a426-40f7-4e4a-86e3-c4fd1932aba4" xlink:to="loc_us-gaap_ProfitLoss_27d4b657-0fe2-44ba-a49e-3c55065cf98f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_d973ee92-1863-428d-8f3a-32be5b38daca" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_2ab0a426-40f7-4e4a-86e3-c4fd1932aba4" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_d973ee92-1863-428d-8f3a-32be5b38daca" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_dcd6bae5-9bb8-495e-a841-ebf4cc3146e7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_2ab0a426-40f7-4e4a-86e3-c4fd1932aba4" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_dcd6bae5-9bb8-495e-a841-ebf4cc3146e7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_NoncontrollingInterestSettlementOfEquityBasedCompensation_6207e58d-5749-48e6-9dd2-247124c7cb88" xlink:href="fip-20260331.xsd#fip_NoncontrollingInterestSettlementOfEquityBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_2ab0a426-40f7-4e4a-86e3-c4fd1932aba4" xlink:to="loc_fip_NoncontrollingInterestSettlementOfEquityBasedCompensation_6207e58d-5749-48e6-9dd2-247124c7cb88" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_f139ee22-1169-44fc-8358-89fb4cabc926" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_2ab0a426-40f7-4e4a-86e3-c4fd1932aba4" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_f139ee22-1169-44fc-8358-89fb4cabc926" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued_3fe15a19-0c00-4112-8c3e-c81768e3a165" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_2ab0a426-40f7-4e4a-86e3-c4fd1932aba4" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued_3fe15a19-0c00-4112-8c3e-c81768e3a165" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition_038660d6-cbfb-4d60-8836-3878e19f208d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_2ab0a426-40f7-4e4a-86e3-c4fd1932aba4" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition_038660d6-cbfb-4d60-8836-3878e19f208d" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_0ac2917a-1ac2-4fee-bdfe-e87fc6aa4c62" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_2ab0a426-40f7-4e4a-86e3-c4fd1932aba4" xlink:to="loc_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_0ac2917a-1ac2-4fee-bdfe-e87fc6aa4c62" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalDividendsInExcessOfRetainedEarnings_c71c7e53-909c-41c8-9297-d7f92acb2801" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalDividendsInExcessOfRetainedEarnings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_2ab0a426-40f7-4e4a-86e3-c4fd1932aba4" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalDividendsInExcessOfRetainedEarnings_c71c7e53-909c-41c8-9297-d7f92acb2801" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_AdjustmentsToAdditionalPaidInCapitalDividendsAndAccretionOfRedeemablePreferredStock_4a912611-00f4-4fe1-a721-c167e7cfb1ef" xlink:href="fip-20260331.xsd#fip_AdjustmentsToAdditionalPaidInCapitalDividendsAndAccretionOfRedeemablePreferredStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_2ab0a426-40f7-4e4a-86e3-c4fd1932aba4" xlink:to="loc_fip_AdjustmentsToAdditionalPaidInCapitalDividendsAndAccretionOfRedeemablePreferredStock_4a912611-00f4-4fe1-a721-c167e7cfb1ef" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_cab4e576-1261-406c-9c25-4a9e4a0ab01a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_2ab0a426-40f7-4e4a-86e3-c4fd1932aba4" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_cab4e576-1261-406c-9c25-4a9e4a0ab01a" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_74f3ddba-7286-4656-8ace-15b63c20498b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/BASISOFPRESENTATIONANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#BASISOFPRESENTATIONANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/BASISOFPRESENTATIONANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2686c6c0-9446-4dd9-ad53-13b1c9188772" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_b394e539-08f1-480a-abb2-ae90aa5efa94" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2686c6c0-9446-4dd9-ad53-13b1c9188772" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_b394e539-08f1-480a-abb2-ae90aa5efa94" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_8f94ccce-bfb5-44b6-ad96-b6913008bf6e" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_b394e539-08f1-480a-abb2-ae90aa5efa94" xlink:to="loc_srt_ConsolidatedEntitiesAxis_8f94ccce-bfb5-44b6-ad96-b6913008bf6e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_8f94ccce-bfb5-44b6-ad96-b6913008bf6e_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_8f94ccce-bfb5-44b6-ad96-b6913008bf6e" xlink:to="loc_srt_ConsolidatedEntitiesDomain_8f94ccce-bfb5-44b6-ad96-b6913008bf6e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_401b7b05-41c8-48c5-9eb0-b77a48dd3d6e" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_8f94ccce-bfb5-44b6-ad96-b6913008bf6e" xlink:to="loc_srt_ConsolidatedEntitiesDomain_401b7b05-41c8-48c5-9eb0-b77a48dd3d6e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_1cc0837e-ea60-4ec3-bbe4-d3e807071ce3" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_b394e539-08f1-480a-abb2-ae90aa5efa94" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_1cc0837e-ea60-4ec3-bbe4-d3e807071ce3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_1cc0837e-ea60-4ec3-bbe4-d3e807071ce3_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_1cc0837e-ea60-4ec3-bbe4-d3e807071ce3" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_1cc0837e-ea60-4ec3-bbe4-d3e807071ce3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_a1e57bb6-c316-4aaf-8af0-25f085f8366c" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_1cc0837e-ea60-4ec3-bbe4-d3e807071ce3" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_a1e57bb6-c316-4aaf-8af0-25f085f8366c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_de2c74b8-09e5-42b1-ad57-322d9d8b34c9" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_b394e539-08f1-480a-abb2-ae90aa5efa94" xlink:to="loc_dei_LegalEntityAxis_de2c74b8-09e5-42b1-ad57-322d9d8b34c9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_de2c74b8-09e5-42b1-ad57-322d9d8b34c9_default" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_de2c74b8-09e5-42b1-ad57-322d9d8b34c9" xlink:to="loc_dei_EntityDomain_de2c74b8-09e5-42b1-ad57-322d9d8b34c9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_1eb2cc35-3f17-4e7b-8b8c-ca927e0fa655" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_de2c74b8-09e5-42b1-ad57-322d9d8b34c9" xlink:to="loc_dei_EntityDomain_1eb2cc35-3f17-4e7b-8b8c-ca927e0fa655" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_05a4471e-27ef-48f9-8458-18c2c5a36446" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_b394e539-08f1-480a-abb2-ae90aa5efa94" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_05a4471e-27ef-48f9-8458-18c2c5a36446" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_05a4471e-27ef-48f9-8458-18c2c5a36446_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_05a4471e-27ef-48f9-8458-18c2c5a36446" xlink:to="loc_us-gaap_SegmentDomain_05a4471e-27ef-48f9-8458-18c2c5a36446_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_8600b600-546d-4f8a-a6d3-e92b4fa54587" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_05a4471e-27ef-48f9-8458-18c2c5a36446" xlink:to="loc_us-gaap_SegmentDomain_8600b600-546d-4f8a-a6d3-e92b4fa54587" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_JeffersonTerminalMember_d3857b61-c4f1-4ec6-9f5e-fc2f892be36e" xlink:href="fip-20260331.xsd#fip_JeffersonTerminalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_8600b600-546d-4f8a-a6d3-e92b4fa54587" xlink:to="loc_fip_JeffersonTerminalMember_d3857b61-c4f1-4ec6-9f5e-fc2f892be36e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_RailroadMember_6f397402-5202-47f3-9224-2d330a3e29b8" xlink:href="fip-20260331.xsd#fip_RailroadMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_8600b600-546d-4f8a-a6d3-e92b4fa54587" xlink:to="loc_fip_RailroadMember_6f397402-5202-47f3-9224-2d330a3e29b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_PowerAndGasMember_8608b3d7-8da9-4bc0-ba5e-830358292088" xlink:href="fip-20260331.xsd#fip_PowerAndGasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_8600b600-546d-4f8a-a6d3-e92b4fa54587" xlink:to="loc_fip_PowerAndGasMember_8608b3d7-8da9-4bc0-ba5e-830358292088" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_TheWheelingCorporationMember_019cc3db-a45c-7cb6-ad01-7905909b2d93" xlink:href="fip-20260331.xsd#fip_TheWheelingCorporationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_8600b600-546d-4f8a-a6d3-e92b4fa54587" xlink:to="loc_fip_TheWheelingCorporationMember_019cc3db-a45c-7cb6-ad01-7905909b2d93" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_44752a4c-8437-419c-82b9-03b84725b695" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_b394e539-08f1-480a-abb2-ae90aa5efa94" xlink:to="loc_srt_CounterpartyNameAxis_44752a4c-8437-419c-82b9-03b84725b695" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_44752a4c-8437-419c-82b9-03b84725b695_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_44752a4c-8437-419c-82b9-03b84725b695" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_44752a4c-8437-419c-82b9-03b84725b695_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_c10f1a99-b780-449d-90c2-d5fc86dd3633" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_44752a4c-8437-419c-82b9-03b84725b695" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_c10f1a99-b780-449d-90c2-d5fc86dd3633" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_cc77a54e-6d8f-468c-a96f-769258851a5e" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MajorCustomersAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_b394e539-08f1-480a-abb2-ae90aa5efa94" xlink:to="loc_srt_MajorCustomersAxis_cc77a54e-6d8f-468c-a96f-769258851a5e" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_cc77a54e-6d8f-468c-a96f-769258851a5e_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_cc77a54e-6d8f-468c-a96f-769258851a5e" xlink:to="loc_srt_NameOfMajorCustomerDomain_cc77a54e-6d8f-468c-a96f-769258851a5e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_dac57651-037e-43b3-bbb2-44fb28ae6f54" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_cc77a54e-6d8f-468c-a96f-769258851a5e" xlink:to="loc_srt_NameOfMajorCustomerDomain_dac57651-037e-43b3-bbb2-44fb28ae6f54" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_CustomerAMember_32447053-70f8-4946-86b4-5f9c34153ad5" xlink:href="fip-20260331.xsd#fip_CustomerAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_dac57651-037e-43b3-bbb2-44fb28ae6f54" xlink:to="loc_fip_CustomerAMember_32447053-70f8-4946-86b4-5f9c34153ad5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_ThreeCustomersMember_3aeff4fa-6e3f-4f9e-a093-c78ece42bd3c" xlink:href="fip-20260331.xsd#fip_ThreeCustomersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_dac57651-037e-43b3-bbb2-44fb28ae6f54" xlink:to="loc_fip_ThreeCustomersMember_3aeff4fa-6e3f-4f9e-a093-c78ece42bd3c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_e0697653-41f7-4498-ab9b-62a30daf4600" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_b394e539-08f1-480a-abb2-ae90aa5efa94" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_e0697653-41f7-4498-ab9b-62a30daf4600" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_e0697653-41f7-4498-ab9b-62a30daf4600_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_e0697653-41f7-4498-ab9b-62a30daf4600" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_e0697653-41f7-4498-ab9b-62a30daf4600_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_ee1d3316-2a6c-4b03-a80c-2e98bd36f4fd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_e0697653-41f7-4498-ab9b-62a30daf4600" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_ee1d3316-2a6c-4b03-a80c-2e98bd36f4fd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SalesRevenueSegmentMember_8d1612d6-711e-489b-b618-95213a3f7ed4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SalesRevenueSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_ee1d3316-2a6c-4b03-a80c-2e98bd36f4fd" xlink:to="loc_us-gaap_SalesRevenueSegmentMember_8d1612d6-711e-489b-b618-95213a3f7ed4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableMember_39e8aa6c-e66e-4ad4-aba4-801482ff44bc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_ee1d3316-2a6c-4b03-a80c-2e98bd36f4fd" xlink:to="loc_us-gaap_AccountsReceivableMember_39e8aa6c-e66e-4ad4-aba4-801482ff44bc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_8fd5c4a5-9a7d-4616-b492-702617ecf001" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_b394e539-08f1-480a-abb2-ae90aa5efa94" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_8fd5c4a5-9a7d-4616-b492-702617ecf001" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_8fd5c4a5-9a7d-4616-b492-702617ecf001_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_8fd5c4a5-9a7d-4616-b492-702617ecf001" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_8fd5c4a5-9a7d-4616-b492-702617ecf001_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_fbf61f90-2469-4b0d-a6c1-2e51c83f34ab" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_8fd5c4a5-9a7d-4616-b492-702617ecf001" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_fbf61f90-2469-4b0d-a6c1-2e51c83f34ab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerConcentrationRiskMember_c4f79d46-8cce-406c-bbe7-1f7e629f8b9c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CustomerConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_fbf61f90-2469-4b0d-a6c1-2e51c83f34ab" xlink:to="loc_us-gaap_CustomerConcentrationRiskMember_c4f79d46-8cce-406c-bbe7-1f7e629f8b9c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_cb5c7573-4978-4c0c-8703-018f9ef54d2d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BalanceSheetLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_b394e539-08f1-480a-abb2-ae90aa5efa94" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_cb5c7573-4978-4c0c-8703-018f9ef54d2d" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_cb5c7573-4978-4c0c-8703-018f9ef54d2d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_cb5c7573-4978-4c0c-8703-018f9ef54d2d" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_cb5c7573-4978-4c0c-8703-018f9ef54d2d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_8c0bab20-5db7-4acc-a3f3-8932dd324bb9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_cb5c7573-4978-4c0c-8703-018f9ef54d2d" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_8c0bab20-5db7-4acc-a3f3-8932dd324bb9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsMember_f941a30d-fe65-4f0d-9953-59d974b68935" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_8c0bab20-5db7-4acc-a3f3-8932dd324bb9" xlink:to="loc_us-gaap_OtherAssetsMember_f941a30d-fe65-4f0d-9953-59d974b68935" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_ec327974-ae20-46e9-984b-031e963fcbf6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_b394e539-08f1-480a-abb2-ae90aa5efa94" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_ec327974-ae20-46e9-984b-031e963fcbf6" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_ec327974-ae20-46e9-984b-031e963fcbf6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_ec327974-ae20-46e9-984b-031e963fcbf6" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_ec327974-ae20-46e9-984b-031e963fcbf6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_c0bcdc00-8d80-43a7-b44e-f237bdd05fcd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_ec327974-ae20-46e9-984b-031e963fcbf6" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_c0bcdc00-8d80-43a7-b44e-f237bdd05fcd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_83b62431-860d-4945-8901-0fc91c19e04b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_c0bcdc00-8d80-43a7-b44e-f237bdd05fcd" xlink:to="loc_us-gaap_LineOfCreditMember_83b62431-860d-4945-8901-0fc91c19e04b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansPayableMember_cd9c3050-d9be-45b6-be78-826712d09a45" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LoansPayableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_c0bcdc00-8d80-43a7-b44e-f237bdd05fcd" xlink:to="loc_us-gaap_LoansPayableMember_cd9c3050-d9be-45b6-be78-826712d09a45" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_53f9eb90-2ce0-462a-954b-e875d45bc2c6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_b394e539-08f1-480a-abb2-ae90aa5efa94" xlink:to="loc_us-gaap_DebtInstrumentAxis_53f9eb90-2ce0-462a-954b-e875d45bc2c6" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_53f9eb90-2ce0-462a-954b-e875d45bc2c6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_53f9eb90-2ce0-462a-954b-e875d45bc2c6" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_53f9eb90-2ce0-462a-954b-e875d45bc2c6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_420e5c6e-cd74-4523-9b1c-54b86efddf25" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_53f9eb90-2ce0-462a-954b-e875d45bc2c6" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_420e5c6e-cd74-4523-9b1c-54b86efddf25" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_CorporateBridgeLoanCreditAgreement1.25BMember_e538f2ca-c4e0-427a-8dd8-3fc11a5d393d" xlink:href="fip-20260331.xsd#fip_CorporateBridgeLoanCreditAgreement1.25BMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_420e5c6e-cd74-4523-9b1c-54b86efddf25" xlink:to="loc_fip_CorporateBridgeLoanCreditAgreement1.25BMember_e538f2ca-c4e0-427a-8dd8-3fc11a5d393d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_d2a89412-3906-44e1-be0b-786ea5965a2f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_b394e539-08f1-480a-abb2-ae90aa5efa94" xlink:to="loc_us-gaap_InvestmentTypeAxis_d2a89412-3906-44e1-be0b-786ea5965a2f" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_d2a89412-3906-44e1-be0b-786ea5965a2f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_d2a89412-3906-44e1-be0b-786ea5965a2f" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_d2a89412-3906-44e1-be0b-786ea5965a2f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_b668a1c3-a7f5-4dd5-8418-1503e1843082" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_d2a89412-3906-44e1-be0b-786ea5965a2f" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_b668a1c3-a7f5-4dd5-8418-1503e1843082" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_TheWheelingCorporationMember_4ea55e8d-3234-4683-8b03-ec4bbe8863d0" xlink:href="fip-20260331.xsd#fip_TheWheelingCorporationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_b668a1c3-a7f5-4dd5-8418-1503e1843082" xlink:to="loc_fip_TheWheelingCorporationMember_4ea55e8d-3234-4683-8b03-ec4bbe8863d0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_019cc3db-a45c-7130-a70c-4389f3147c90" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_b394e539-08f1-480a-abb2-ae90aa5efa94" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_019cc3db-a45c-7130-a70c-4389f3147c90" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019cc3db-a45c-7130-a70c-4389f3147c90_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019cc3db-a45c-7130-a70c-4389f3147c90" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019cc3db-a45c-7130-a70c-4389f3147c90_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019cc3db-a45c-7acb-9b07-a9fc3f3d4c1c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019cc3db-a45c-7130-a70c-4389f3147c90" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019cc3db-a45c-7acb-9b07-a9fc3f3d4c1c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_019cc3db-a45c-7982-ac88-41877a1c6f15" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_019cc3db-a45c-7acb-9b07-a9fc3f3d4c1c" xlink:to="loc_us-gaap_SubsequentEventMember_019cc3db-a45c-7982-ac88-41877a1c6f15" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_0960d5ec-e204-4939-8347-78a5bf4d04b7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2686c6c0-9446-4dd9-ad53-13b1c9188772" xlink:to="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_0960d5ec-e204-4939-8347-78a5bf4d04b7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_687d982f-7537-4de0-9137-54e5b5207ffb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2686c6c0-9446-4dd9-ad53-13b1c9188772" xlink:to="loc_us-gaap_Assets_687d982f-7537-4de0-9137-54e5b5207ffb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_c7416754-176e-485e-90b2-d4a29590f89c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Liabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2686c6c0-9446-4dd9-ad53-13b1c9188772" xlink:to="loc_us-gaap_Liabilities_c7416754-176e-485e-90b2-d4a29590f89c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostNetNoncurrent_15d25947-f4c7-44f7-a161-eba3ea539c28" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CapitalizedContractCostNetNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2686c6c0-9446-4dd9-ad53-13b1c9188772" xlink:to="loc_us-gaap_CapitalizedContractCostNetNoncurrent_15d25947-f4c7-44f7-a161-eba3ea539c28" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_fb61d3a4-7492-4d24-ab07-881b8b6574d7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2686c6c0-9446-4dd9-ad53-13b1c9188772" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_fb61d3a4-7492-4d24-ab07-881b8b6574d7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_OtherLiabilitiesInsurancePremiumsCurrent_fdaada47-983e-41a4-ae0c-381eceb898ce" xlink:href="fip-20260331.xsd#fip_OtherLiabilitiesInsurancePremiumsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2686c6c0-9446-4dd9-ad53-13b1c9188772" xlink:to="loc_fip_OtherLiabilitiesInsurancePremiumsCurrent_fdaada47-983e-41a4-ae0c-381eceb898ce" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredRevenue_124a7255-9add-4463-9580-29693262918d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2686c6c0-9446-4dd9-ad53-13b1c9188772" xlink:to="loc_us-gaap_DeferredRevenue_124a7255-9add-4463-9580-29693262918d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_b591e2f4-9133-4a4e-8f80-093f42c717c6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2686c6c0-9446-4dd9-ad53-13b1c9188772" xlink:to="loc_us-gaap_Goodwill_b591e2f4-9133-4a4e-8f80-093f42c717c6" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnamortizedDebtIssuanceExpense_03d1d1af-f1ff-4b9a-aa69-1b34af6c3c48" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnamortizedDebtIssuanceExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2686c6c0-9446-4dd9-ad53-13b1c9188772" xlink:to="loc_us-gaap_UnamortizedDebtIssuanceExpense_03d1d1af-f1ff-4b9a-aa69-1b34af6c3c48" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfFinancingCosts_d30a629b-c51b-4261-8b85-7242b0c2a224" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AmortizationOfFinancingCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2686c6c0-9446-4dd9-ad53-13b1c9188772" xlink:to="loc_us-gaap_AmortizationOfFinancingCosts_d30a629b-c51b-4261-8b85-7242b0c2a224" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_40ee1755-ae2c-4f85-8bea-c01aca315f1d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2686c6c0-9446-4dd9-ad53-13b1c9188772" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_40ee1755-ae2c-4f85-8bea-c01aca315f1d" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrepaidExpenseCurrentAndNoncurrent_f4221d8b-c6c4-4506-b2f0-93f6930a2ca7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PrepaidExpenseCurrentAndNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2686c6c0-9446-4dd9-ad53-13b1c9188772" xlink:to="loc_us-gaap_PrepaidExpenseCurrentAndNoncurrent_f4221d8b-c6c4-4506-b2f0-93f6930a2ca7" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherReceivables_12fdf313-2982-4770-8035-9506f7b865c7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherReceivables"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2686c6c0-9446-4dd9-ad53-13b1c9188772" xlink:to="loc_us-gaap_OtherReceivables_12fdf313-2982-4770-8035-9506f7b865c7" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsCurrent_f148d944-24bb-4b22-af2b-98381e4b8946" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2686c6c0-9446-4dd9-ad53-13b1c9188772" xlink:to="loc_us-gaap_OtherAssetsCurrent_f148d944-24bb-4b22-af2b-98381e4b8946" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_2ef48ab4-b605-483a-94d0-115088e5710e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2686c6c0-9446-4dd9-ad53-13b1c9188772" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_2ef48ab4-b605-483a-94d0-115088e5710e" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_14e5ecbf-719a-409b-b454-ab239a35b2ae" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2686c6c0-9446-4dd9-ad53-13b1c9188772" xlink:to="loc_us-gaap_LongTermDebt_14e5ecbf-719a-409b-b454-ab239a35b2ae" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_47e70cea-46e6-4332-95dd-cd97edda7147" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2686c6c0-9446-4dd9-ad53-13b1c9188772" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_47e70cea-46e6-4332-95dd-cd97edda7147" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_EquityMethodInvestmentIncludingAvailableForSaleSecurities_f159471e-5df0-42d4-a702-2a366e9d5de2" xlink:href="fip-20260331.xsd#fip_EquityMethodInvestmentIncludingAvailableForSaleSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2686c6c0-9446-4dd9-ad53-13b1c9188772" xlink:to="loc_fip_EquityMethodInvestmentIncludingAvailableForSaleSecurities_f159471e-5df0-42d4-a702-2a366e9d5de2" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NontradeReceivablesCurrent_019c9182-cf6c-7cc7-9617-1d8f37a22ef6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NontradeReceivablesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2686c6c0-9446-4dd9-ad53-13b1c9188772" xlink:to="loc_us-gaap_NontradeReceivablesCurrent_019c9182-cf6c-7cc7-9617-1d8f37a22ef6" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Deposits_019c9182-cf6c-7c1a-86ef-f230c512a5ff" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Deposits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2686c6c0-9446-4dd9-ad53-13b1c9188772" xlink:to="loc_us-gaap_Deposits_019c9182-cf6c-7c1a-86ef-f230c512a5ff" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryGross_019c9182-cf6c-7dee-98b0-1d3aa18364d3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InventoryGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2686c6c0-9446-4dd9-ad53-13b1c9188772" xlink:to="loc_us-gaap_InventoryGross_019c9182-cf6c-7dee-98b0-1d3aa18364d3" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityNoncurrent_019cc3db-a45c-72ae-8a46-ac8f489c1c0c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2686c6c0-9446-4dd9-ad53-13b1c9188772" xlink:to="loc_us-gaap_FinanceLeaseLiabilityNoncurrent_019cc3db-a45c-72ae-8a46-ac8f489c1c0c" xlink:type="arc" order="21"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/BASISOFPRESENTATIONANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESUsefulLivesDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#BASISOFPRESENTATIONANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESUsefulLivesDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/BASISOFPRESENTATIONANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESUsefulLivesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5747ab4a-31b3-48a3-9858-5cdb45f0fb50" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_9f8c7c64-9c14-4fe3-a625-cffc07f61b05" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5747ab4a-31b3-48a3-9858-5cdb45f0fb50" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_9f8c7c64-9c14-4fe3-a625-cffc07f61b05" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_9db29538-64f1-47de-984c-90c0f0f5e294" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_9f8c7c64-9c14-4fe3-a625-cffc07f61b05" xlink:to="loc_srt_RangeAxis_9db29538-64f1-47de-984c-90c0f0f5e294" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_9db29538-64f1-47de-984c-90c0f0f5e294_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_9db29538-64f1-47de-984c-90c0f0f5e294" xlink:to="loc_srt_RangeMember_9db29538-64f1-47de-984c-90c0f0f5e294_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_266c73c3-9a6f-4fbd-855a-85e2a83be7be" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_9db29538-64f1-47de-984c-90c0f0f5e294" xlink:to="loc_srt_RangeMember_266c73c3-9a6f-4fbd-855a-85e2a83be7be" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_6f672862-1b47-48d7-a9ba-7ab24d42d77c" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_266c73c3-9a6f-4fbd-855a-85e2a83be7be" xlink:to="loc_srt_MinimumMember_6f672862-1b47-48d7-a9ba-7ab24d42d77c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_67ac04f7-f4c0-4c71-89b8-5b07f7218597" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_266c73c3-9a6f-4fbd-855a-85e2a83be7be" xlink:to="loc_srt_MaximumMember_67ac04f7-f4c0-4c71-89b8-5b07f7218597" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_c525edd1-c492-4b4e-82b3-47408d345bbb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_9f8c7c64-9c14-4fe3-a625-cffc07f61b05" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_c525edd1-c492-4b4e-82b3-47408d345bbb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_c525edd1-c492-4b4e-82b3-47408d345bbb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_c525edd1-c492-4b4e-82b3-47408d345bbb" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_c525edd1-c492-4b4e-82b3-47408d345bbb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_d47a8ea8-7efb-4fd8-8151-540b0ef9ba1b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_c525edd1-c492-4b4e-82b3-47408d345bbb" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_d47a8ea8-7efb-4fd8-8151-540b0ef9ba1b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_RailcarsandLocomotivesMember_051005c0-1a49-4138-820b-1fe54c9d1bcd" xlink:href="fip-20260331.xsd#fip_RailcarsandLocomotivesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_d47a8ea8-7efb-4fd8-8151-540b0ef9ba1b" xlink:to="loc_fip_RailcarsandLocomotivesMember_051005c0-1a49-4138-820b-1fe54c9d1bcd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_RailroadTrackandRelatedAssetsMember_28aa63b8-42fd-49e8-a926-9906727ac605" xlink:href="fip-20260331.xsd#fip_RailroadTrackandRelatedAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_d47a8ea8-7efb-4fd8-8151-540b0ef9ba1b" xlink:to="loc_fip_RailroadTrackandRelatedAssetsMember_28aa63b8-42fd-49e8-a926-9906727ac605" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_BridgesAndTunnelsMember_9b7a3543-25d3-4225-beea-3693748d8544" xlink:href="fip-20260331.xsd#fip_BridgesAndTunnelsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_d47a8ea8-7efb-4fd8-8151-540b0ef9ba1b" xlink:to="loc_fip_BridgesAndTunnelsMember_9b7a3543-25d3-4225-beea-3693748d8544" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_RailroadEquipmentMember_ffce8d92-eff8-48f7-afdb-084db6ef08c9" xlink:href="fip-20260331.xsd#fip_RailroadEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_d47a8ea8-7efb-4fd8-8151-540b0ef9ba1b" xlink:to="loc_fip_RailroadEquipmentMember_ffce8d92-eff8-48f7-afdb-084db6ef08c9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_PowerGenerationMember_10f5fc7d-a84b-41c4-b8c7-8f4257584bcc" xlink:href="fip-20260331.xsd#fip_PowerGenerationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_d47a8ea8-7efb-4fd8-8151-540b0ef9ba1b" xlink:to="loc_fip_PowerGenerationMember_10f5fc7d-a84b-41c4-b8c7-8f4257584bcc" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_71250fb5-cb56-46a2-b22c-7b0e7815ce44" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FurnitureAndFixturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_d47a8ea8-7efb-4fd8-8151-540b0ef9ba1b" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_71250fb5-cb56-46a2-b22c-7b0e7815ce44" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComputerEquipmentMember_e3d2d528-7574-4b16-a460-2ffd2d5ba740" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComputerEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_d47a8ea8-7efb-4fd8-8151-540b0ef9ba1b" xlink:to="loc_us-gaap_ComputerEquipmentMember_e3d2d528-7574-4b16-a460-2ffd2d5ba740" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_05db7783-9c70-4627-83ee-aa67c762c524" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5747ab4a-31b3-48a3-9858-5cdb45f0fb50" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_05db7783-9c70-4627-83ee-aa67c762c524" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/BASISOFPRESENTATIONANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofAccumulatedOtherComprehensiveIncomeLossDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#BASISOFPRESENTATIONANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofAccumulatedOtherComprehensiveIncomeLossDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/BASISOFPRESENTATIONANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofAccumulatedOtherComprehensiveIncomeLossDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_a29a191b-4786-4d5f-8228-90f3cafb2edd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_9c8bca51-0f15-4d4e-983e-80270dd2e2b7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_a29a191b-4786-4d5f-8228-90f3cafb2edd" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_9c8bca51-0f15-4d4e-983e-80270dd2e2b7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_12eb532d-7741-4700-ad34-e3dee013daff" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_9c8bca51-0f15-4d4e-983e-80270dd2e2b7" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_12eb532d-7741-4700-ad34-e3dee013daff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_12eb532d-7741-4700-ad34-e3dee013daff_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_12eb532d-7741-4700-ad34-e3dee013daff" xlink:to="loc_us-gaap_EquityComponentDomain_12eb532d-7741-4700-ad34-e3dee013daff_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_fde8ede9-bfee-4e66-933a-e4f52568d720" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_12eb532d-7741-4700-ad34-e3dee013daff" xlink:to="loc_us-gaap_EquityComponentDomain_fde8ede9-bfee-4e66-933a-e4f52568d720" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossCashFlowHedgeIncludingNoncontrollingInterestMember_7aa3b90d-3e52-40a5-b4eb-33dc4e2563b7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedGainLossCashFlowHedgeIncludingNoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_fde8ede9-bfee-4e66-933a-e4f52568d720" xlink:to="loc_us-gaap_AccumulatedGainLossCashFlowHedgeIncludingNoncontrollingInterestMember_7aa3b90d-3e52-40a5-b4eb-33dc4e2563b7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AociEquityMethodInvestmentIncludingNoncontrollingInterestMember_cbc0c1a5-63e0-41f8-8b20-ceb8e8fed576" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AociEquityMethodInvestmentIncludingNoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_fde8ede9-bfee-4e66-933a-e4f52568d720" xlink:to="loc_us-gaap_AociEquityMethodInvestmentIncludingNoncontrollingInterestMember_cbc0c1a5-63e0-41f8-8b20-ceb8e8fed576" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentIncludingPortionAttributableToNoncontrollingInterestMember_a97e1ed1-7292-4a6a-81c1-3cc89d905338" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentIncludingPortionAttributableToNoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_fde8ede9-bfee-4e66-933a-e4f52568d720" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentIncludingPortionAttributableToNoncontrollingInterestMember_a97e1ed1-7292-4a6a-81c1-3cc89d905338" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_a3bdf1d2-6acf-47b6-a1a1-ce2a5a3d9dda" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_fde8ede9-bfee-4e66-933a-e4f52568d720" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_a3bdf1d2-6acf-47b6-a1a1-ce2a5a3d9dda" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_4d80a7db-79b5-44cf-8046-958179de6ab6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_a29a191b-4786-4d5f-8228-90f3cafb2edd" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_4d80a7db-79b5-44cf-8046-958179de6ab6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_b7699d83-06bb-4d9a-a2f2-b7cab4d25aa1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_4d80a7db-79b5-44cf-8046-958179de6ab6" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_b7699d83-06bb-4d9a-a2f2-b7cab4d25aa1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_0755bdea-b832-41b1-8013-ca7ee0d6ccfc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_4d80a7db-79b5-44cf-8046-958179de6ab6" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_0755bdea-b832-41b1-8013-ca7ee0d6ccfc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_c53dce6d-6904-448b-b0de-b82ca08abd15" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_4d80a7db-79b5-44cf-8046-958179de6ab6" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_c53dce6d-6904-448b-b0de-b82ca08abd15" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_fb354867-2bf0-4bc6-83b9-4d9991d1b173" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_4d80a7db-79b5-44cf-8046-958179de6ab6" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_fb354867-2bf0-4bc6-83b9-4d9991d1b173" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_bc92060e-f87e-4cbf-a2e1-f473c7518346" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/ACQUISITIONOFSUBSIDIARIESNarrativeDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#ACQUISITIONOFSUBSIDIARIESNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/ACQUISITIONOFSUBSIDIARIESNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019de4ba-606e-73eb-867e-d64eb8aafcdf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019de4ba-606e-73c3-9752-c590fb2ec73a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019de4ba-606e-73eb-867e-d64eb8aafcdf" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019de4ba-606e-73c3-9752-c590fb2ec73a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019de4ba-606e-711f-bedd-4b69896c0273" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019de4ba-606e-73c3-9752-c590fb2ec73a" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019de4ba-606e-711f-bedd-4b69896c0273" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_019de4ba-606e-711f-bedd-4b69896c0273_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019de4ba-606e-711f-bedd-4b69896c0273" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_019de4ba-606e-711f-bedd-4b69896c0273_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_019de4ba-606e-7e18-96ad-a47d98309944" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019de4ba-606e-711f-bedd-4b69896c0273" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_019de4ba-606e-7e18-96ad-a47d98309944" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_LongRidgeEnergyPowerLLCMember_019de4ba-606e-7bf7-a557-0da3e6924b01" xlink:href="fip-20260331.xsd#fip_LongRidgeEnergyPowerLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_019de4ba-606e-7e18-96ad-a47d98309944" xlink:to="loc_fip_LongRidgeEnergyPowerLLCMember_019de4ba-606e-7bf7-a557-0da3e6924b01" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019de4ba-606e-7686-a13d-5e2f1719da83" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019de4ba-606e-73c3-9752-c590fb2ec73a" xlink:to="loc_dei_LegalEntityAxis_019de4ba-606e-7686-a13d-5e2f1719da83" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019de4ba-606e-7686-a13d-5e2f1719da83_default" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019de4ba-606e-7686-a13d-5e2f1719da83" xlink:to="loc_dei_EntityDomain_019de4ba-606e-7686-a13d-5e2f1719da83_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019de4ba-606e-7d8f-a91d-eaf0fc6a00eb" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019de4ba-606e-7686-a13d-5e2f1719da83" xlink:to="loc_dei_EntityDomain_019de4ba-606e-7d8f-a91d-eaf0fc6a00eb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_GCMGrosvenorIncMember_019de4ba-606e-7865-963f-a1fffc4d329a" xlink:href="fip-20260331.xsd#fip_GCMGrosvenorIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019de4ba-606e-7d8f-a91d-eaf0fc6a00eb" xlink:to="loc_fip_GCMGrosvenorIncMember_019de4ba-606e-7865-963f-a1fffc4d329a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019de4ba-606e-7512-87ec-2686d3bb500f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019de4ba-606e-73c3-9752-c590fb2ec73a" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019de4ba-606e-7512-87ec-2686d3bb500f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019de4ba-606e-7512-87ec-2686d3bb500f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019de4ba-606e-7512-87ec-2686d3bb500f" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019de4ba-606e-7512-87ec-2686d3bb500f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019de4ba-606e-777c-a6a0-2fdb4cc06ba4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019de4ba-606e-7512-87ec-2686d3bb500f" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019de4ba-606e-777c-a6a0-2fdb4cc06ba4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_LongRidgeEnergyPowerLLCMember_019de4ba-606e-7835-8c5d-f1df2e0d47fb" xlink:href="fip-20260331.xsd#fip_LongRidgeEnergyPowerLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019de4ba-606e-777c-a6a0-2fdb4cc06ba4" xlink:to="loc_fip_LongRidgeEnergyPowerLLCMember_019de4ba-606e-7835-8c5d-f1df2e0d47fb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_019de4ba-606e-7526-a993-dc30926cbad8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019de4ba-606e-73c3-9752-c590fb2ec73a" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_019de4ba-606e-7526-a993-dc30926cbad8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_019de4ba-606e-7526-a993-dc30926cbad8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_019de4ba-606e-7526-a993-dc30926cbad8" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_019de4ba-606e-7526-a993-dc30926cbad8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_019de4ba-606e-7c72-ad7c-32e988eaf32a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_019de4ba-606e-7526-a993-dc30926cbad8" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_019de4ba-606e-7c72-ad7c-32e988eaf32a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember_019de4ba-606e-7c36-bccc-e414308f66f0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_019de4ba-606e-7c72-ad7c-32e988eaf32a" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember_019de4ba-606e-7c36-bccc-e414308f66f0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019de4ba-606e-75d9-a941-d9cbeee22391" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019de4ba-606e-73c3-9752-c590fb2ec73a" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019de4ba-606e-75d9-a941-d9cbeee22391" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019de4ba-606e-75d9-a941-d9cbeee22391_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019de4ba-606e-75d9-a941-d9cbeee22391" xlink:to="loc_us-gaap_EquityComponentDomain_019de4ba-606e-75d9-a941-d9cbeee22391_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019de4ba-606e-70d6-bdb7-9ffbfe06d983" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019de4ba-606e-75d9-a941-d9cbeee22391" xlink:to="loc_us-gaap_EquityComponentDomain_019de4ba-606e-70d6-bdb7-9ffbfe06d983" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AociEquityMethodInvestmentIncludingNoncontrollingInterestMember_019de4ba-606e-7725-83ce-bd5c7e4d6df5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AociEquityMethodInvestmentIncludingNoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019de4ba-606e-70d6-bdb7-9ffbfe06d983" xlink:to="loc_us-gaap_AociEquityMethodInvestmentIncludingNoncontrollingInterestMember_019de4ba-606e-7725-83ce-bd5c7e4d6df5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_019de4ba-606e-7513-89c4-af435f4a024f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019de4ba-606e-73eb-867e-d64eb8aafcdf" xlink:to="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_019de4ba-606e-7513-89c4-af435f4a024f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_019de4ba-606e-71ef-a528-91f38d44d1ae" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019de4ba-606e-73eb-867e-d64eb8aafcdf" xlink:to="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_019de4ba-606e-71ef-a528-91f38d44d1ae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationStepAcquisitionEquityInterestInAcquireeRemeasurementGainOrLoss_019de4ba-606e-7207-bcc5-5a53cd51c93b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationStepAcquisitionEquityInterestInAcquireeRemeasurementGainOrLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019de4ba-606e-73eb-867e-d64eb8aafcdf" xlink:to="loc_us-gaap_BusinessCombinationStepAcquisitionEquityInterestInAcquireeRemeasurementGainOrLoss_019de4ba-606e-7207-bcc5-5a53cd51c93b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019de4ba-606e-75d2-918f-eaf516f21c40" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019de4ba-606e-73eb-867e-d64eb8aafcdf" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_019de4ba-606e-75d2-918f-eaf516f21c40" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/ACQUISITIONOFSUBSIDIARIESScheduleofAssetsAcquiredandLiabilitiesAssumedDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#ACQUISITIONOFSUBSIDIARIESScheduleofAssetsAcquiredandLiabilitiesAssumedDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/ACQUISITIONOFSUBSIDIARIESScheduleofAssetsAcquiredandLiabilitiesAssumedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_2124b5d9-61b2-4130-a68f-af06b518aa3c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_6b894575-55dc-4734-ba67-05929ffc0d17" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_2124b5d9-61b2-4130-a68f-af06b518aa3c" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_6b894575-55dc-4734-ba67-05929ffc0d17" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_d04d380e-c75d-46e5-8141-bc139e7091aa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_6b894575-55dc-4734-ba67-05929ffc0d17" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_d04d380e-c75d-46e5-8141-bc139e7091aa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_d04d380e-c75d-46e5-8141-bc139e7091aa_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_d04d380e-c75d-46e5-8141-bc139e7091aa" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_d04d380e-c75d-46e5-8141-bc139e7091aa_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_623e5275-70de-407f-a3bd-8cbbfaa548ac" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_d04d380e-c75d-46e5-8141-bc139e7091aa" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_623e5275-70de-407f-a3bd-8cbbfaa548ac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_PowerGasMember_96fde2cd-41a0-4800-9d28-4ddb05a4f69b" xlink:href="fip-20260331.xsd#fip_PowerGasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_623e5275-70de-407f-a3bd-8cbbfaa548ac" xlink:to="loc_fip_PowerGasMember_96fde2cd-41a0-4800-9d28-4ddb05a4f69b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_8aec4ec5-35ba-4251-a68d-b080be8af7b8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_2124b5d9-61b2-4130-a68f-af06b518aa3c" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_8aec4ec5-35ba-4251-a68d-b080be8af7b8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_BusinessCombinationRecognizedIdentifiableAssetsAndLiabilitiesRestrictedCash_9466044f-661d-4fad-9fa4-20f9827fe72d" xlink:href="fip-20260331.xsd#fip_BusinessCombinationRecognizedIdentifiableAssetsAndLiabilitiesRestrictedCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_2124b5d9-61b2-4130-a68f-af06b518aa3c" xlink:to="loc_fip_BusinessCombinationRecognizedIdentifiableAssetsAndLiabilitiesRestrictedCash_9466044f-661d-4fad-9fa4-20f9827fe72d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_565dc073-1e28-46d4-8383-c088229b9f1e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_2124b5d9-61b2-4130-a68f-af06b518aa3c" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_565dc073-1e28-46d4-8383-c088229b9f1e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_6e429b91-950d-4e17-9880-be4973f06ad7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_2124b5d9-61b2-4130-a68f-af06b518aa3c" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_6e429b91-950d-4e17-9880-be4973f06ad7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_7f76eebc-fc93-42ed-8772-6a5771b9901c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_2124b5d9-61b2-4130-a68f-af06b518aa3c" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_7f76eebc-fc93-42ed-8772-6a5771b9901c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_43d1d2d3-2377-4cd5-9901-e0feaf83aa20" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_2124b5d9-61b2-4130-a68f-af06b518aa3c" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_43d1d2d3-2377-4cd5-9901-e0feaf83aa20" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets_12305aae-741c-40ec-858b-38658c109b79" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_2124b5d9-61b2-4130-a68f-af06b518aa3c" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets_12305aae-741c-40ec-858b-38658c109b79" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable_a787a0e8-3e3c-4e2a-9e7f-49f0c23246ef" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_2124b5d9-61b2-4130-a68f-af06b518aa3c" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable_a787a0e8-3e3c-4e2a-9e7f-49f0c23246ef" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDebtNet_018787db-cbd8-4b96-8652-ea27b526842f" xlink:href="fip-20260331.xsd#fip_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDebtNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_2124b5d9-61b2-4130-a68f-af06b518aa3c" xlink:to="loc_fip_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDebtNet_018787db-cbd8-4b96-8652-ea27b526842f" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDerivativeLiabilities_15f3d6dd-1792-480f-9a01-99756bcb9709" xlink:href="fip-20260331.xsd#fip_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDerivativeLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_2124b5d9-61b2-4130-a68f-af06b518aa3c" xlink:to="loc_fip_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDerivativeLiabilities_15f3d6dd-1792-480f-9a01-99756bcb9709" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_0e4c8ca6-33d4-46f2-8558-7f2e03c57a21" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_2124b5d9-61b2-4130-a68f-af06b518aa3c" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_0e4c8ca6-33d4-46f2-8558-7f2e03c57a21" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_55dd5f82-4be6-4546-a437-08fa22900224" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_2124b5d9-61b2-4130-a68f-af06b518aa3c" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_55dd5f82-4be6-4546-a437-08fa22900224" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_095aeb26-0836-4245-895c-3ffba56248db" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_2124b5d9-61b2-4130-a68f-af06b518aa3c" xlink:to="loc_us-gaap_Goodwill_095aeb26-0836-4245-895c-3ffba56248db" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_d046ad87-3b4d-41ab-91b9-115dba1833e2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_2124b5d9-61b2-4130-a68f-af06b518aa3c" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_d046ad87-3b4d-41ab-91b9-115dba1833e2" xlink:type="arc" order="13"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/ACQUISITIONOFSUBSIDIARIESIntangibleAssetsAcquiredDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#ACQUISITIONOFSUBSIDIARIESIntangibleAssetsAcquiredDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/ACQUISITIONOFSUBSIDIARIESIntangibleAssetsAcquiredDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_41ddfb9b-bb74-41b5-90fd-57b827ec6c52" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_823f6a6b-cf56-4e86-a441-0c46d0601ed0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_41ddfb9b-bb74-41b5-90fd-57b827ec6c52" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_823f6a6b-cf56-4e86-a441-0c46d0601ed0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_76e02684-5afc-44ab-89e1-2c86ee81f642" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_823f6a6b-cf56-4e86-a441-0c46d0601ed0" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_76e02684-5afc-44ab-89e1-2c86ee81f642" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_76e02684-5afc-44ab-89e1-2c86ee81f642_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_76e02684-5afc-44ab-89e1-2c86ee81f642" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_76e02684-5afc-44ab-89e1-2c86ee81f642_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_ed119dab-4d47-46eb-815e-e9a029d31af7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_76e02684-5afc-44ab-89e1-2c86ee81f642" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_ed119dab-4d47-46eb-815e-e9a029d31af7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_PowerGasMember_120b15a7-6d10-4458-a0d9-a8991903e347" xlink:href="fip-20260331.xsd#fip_PowerGasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_ed119dab-4d47-46eb-815e-e9a029d31af7" xlink:to="loc_fip_PowerGasMember_120b15a7-6d10-4458-a0d9-a8991903e347" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_19e7d924-1c62-42d0-b299-72539d035b8e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_41ddfb9b-bb74-41b5-90fd-57b827ec6c52" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_19e7d924-1c62-42d0-b299-72539d035b8e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_eb355082-2719-4b62-8a5e-0b13073affd3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_41ddfb9b-bb74-41b5-90fd-57b827ec6c52" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_eb355082-2719-4b62-8a5e-0b13073affd3" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/ACQUISITIONOFSUBSIDIARIESPropertyPlantandEquipmentAcquiredDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#ACQUISITIONOFSUBSIDIARIESPropertyPlantandEquipmentAcquiredDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/ACQUISITIONOFSUBSIDIARIESPropertyPlantandEquipmentAcquiredDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_4fc9adaf-1140-4902-b567-8dd005aafe2f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_f9c7622c-bc92-481a-8c0b-3858ca87f428" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4fc9adaf-1140-4902-b567-8dd005aafe2f" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_f9c7622c-bc92-481a-8c0b-3858ca87f428" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_6c6582b9-67e7-4b0b-97c6-a32a527408b1" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_f9c7622c-bc92-481a-8c0b-3858ca87f428" xlink:to="loc_srt_RangeAxis_6c6582b9-67e7-4b0b-97c6-a32a527408b1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_6c6582b9-67e7-4b0b-97c6-a32a527408b1_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_6c6582b9-67e7-4b0b-97c6-a32a527408b1" xlink:to="loc_srt_RangeMember_6c6582b9-67e7-4b0b-97c6-a32a527408b1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_e3c7bee5-0dd3-45db-b9d4-4757dcd7d83f" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_6c6582b9-67e7-4b0b-97c6-a32a527408b1" xlink:to="loc_srt_RangeMember_e3c7bee5-0dd3-45db-b9d4-4757dcd7d83f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_6172fffc-102b-4a3b-9708-5e4972337eee" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_e3c7bee5-0dd3-45db-b9d4-4757dcd7d83f" xlink:to="loc_srt_MinimumMember_6172fffc-102b-4a3b-9708-5e4972337eee" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_2f5528f1-12fe-409a-b6b0-0c80082cf80a" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_e3c7bee5-0dd3-45db-b9d4-4757dcd7d83f" xlink:to="loc_srt_MaximumMember_2f5528f1-12fe-409a-b6b0-0c80082cf80a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_1a8be307-73c5-414c-b939-29ae8f55d926" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_f9c7622c-bc92-481a-8c0b-3858ca87f428" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_1a8be307-73c5-414c-b939-29ae8f55d926" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1a8be307-73c5-414c-b939-29ae8f55d926_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_1a8be307-73c5-414c-b939-29ae8f55d926" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1a8be307-73c5-414c-b939-29ae8f55d926_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_48cf88f5-e443-4953-b06d-8f6abfb1bf40" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_1a8be307-73c5-414c-b939-29ae8f55d926" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_48cf88f5-e443-4953-b06d-8f6abfb1bf40" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_PowerGasMember_26e73d63-f478-4f93-8d6d-3ce35de02f11" xlink:href="fip-20260331.xsd#fip_PowerGasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_48cf88f5-e443-4953-b06d-8f6abfb1bf40" xlink:to="loc_fip_PowerGasMember_26e73d63-f478-4f93-8d6d-3ce35de02f11" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_6d013da3-1433-4df3-a5ca-27c509c16e28" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_f9c7622c-bc92-481a-8c0b-3858ca87f428" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_6d013da3-1433-4df3-a5ca-27c509c16e28" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_6d013da3-1433-4df3-a5ca-27c509c16e28_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_6d013da3-1433-4df3-a5ca-27c509c16e28" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_6d013da3-1433-4df3-a5ca-27c509c16e28_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_fa8907b5-b28b-4c6f-80f4-f3e4c6584f7b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_6d013da3-1433-4df3-a5ca-27c509c16e28" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_fa8907b5-b28b-4c6f-80f4-f3e4c6584f7b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionInProgressMember_bbfd0f8f-0aeb-4e21-b8c5-29af6c7258ac" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConstructionInProgressMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_fa8907b5-b28b-4c6f-80f4-f3e4c6584f7b" xlink:to="loc_us-gaap_ConstructionInProgressMember_bbfd0f8f-0aeb-4e21-b8c5-29af6c7258ac" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_UnprovedPropertiesMember_ce1c04c7-a6c9-4425-a568-2176f0108445" xlink:href="fip-20260331.xsd#fip_UnprovedPropertiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_fa8907b5-b28b-4c6f-80f4-f3e4c6584f7b" xlink:to="loc_fip_UnprovedPropertiesMember_ce1c04c7-a6c9-4425-a568-2176f0108445" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_ProvedDevelopedPropertiesMember_d6b89b90-0150-42a7-b391-7b47e4f758b0" xlink:href="fip-20260331.xsd#fip_ProvedDevelopedPropertiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_fa8907b5-b28b-4c6f-80f4-f3e4c6584f7b" xlink:to="loc_fip_ProvedDevelopedPropertiesMember_d6b89b90-0150-42a7-b391-7b47e4f758b0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_PowerGenerationMember_6ccbe4cf-cb27-4e42-a507-ef32b7de1d42" xlink:href="fip-20260331.xsd#fip_PowerGenerationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_fa8907b5-b28b-4c6f-80f4-f3e4c6584f7b" xlink:to="loc_fip_PowerGenerationMember_6ccbe4cf-cb27-4e42-a507-ef32b7de1d42" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComputerEquipmentMember_b2c76def-61d4-4942-83c6-737400fbb4df" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComputerEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_fa8907b5-b28b-4c6f-80f4-f3e4c6584f7b" xlink:to="loc_us-gaap_ComputerEquipmentMember_b2c76def-61d4-4942-83c6-737400fbb4df" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LandAndLandImprovementsMember_19baae1e-87bb-4504-a110-9aafd8c47c9c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LandAndLandImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_fa8907b5-b28b-4c6f-80f4-f3e4c6584f7b" xlink:to="loc_us-gaap_LandAndLandImprovementsMember_19baae1e-87bb-4504-a110-9aafd8c47c9c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BuildingMember_0d38b75e-3ecc-48de-a108-038d23a693ee" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BuildingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_fa8907b5-b28b-4c6f-80f4-f3e4c6584f7b" xlink:to="loc_us-gaap_BuildingMember_0d38b75e-3ecc-48de-a108-038d23a693ee" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MachineryAndEquipmentMember_4852ea38-6266-4512-ac13-a52b805b7f4b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MachineryAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_fa8907b5-b28b-4c6f-80f4-f3e4c6584f7b" xlink:to="loc_us-gaap_MachineryAndEquipmentMember_4852ea38-6266-4512-ac13-a52b805b7f4b" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_sic_Z3743_ba216bb5-d00e-4ae0-84c8-ad53c690f344" xlink:href="https://xbrl.sec.gov/sic/2025/sic-2025.xsd#sic_Z3743"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_fa8907b5-b28b-4c6f-80f4-f3e4c6584f7b" xlink:to="loc_sic_Z3743_ba216bb5-d00e-4ae0-84c8-ad53c690f344" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VehiclesMember_9770ef59-c2e8-4634-92fa-5c4400dc5e49" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VehiclesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_fa8907b5-b28b-4c6f-80f4-f3e4c6584f7b" xlink:to="loc_us-gaap_VehiclesMember_9770ef59-c2e8-4634-92fa-5c4400dc5e49" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_bc5f91f2-3b54-42b5-871e-261766116e09" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4fc9adaf-1140-4902-b567-8dd005aafe2f" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_bc5f91f2-3b54-42b5-871e-261766116e09" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_aa08bdc8-7332-418c-9f47-108fdde63e63" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4fc9adaf-1140-4902-b567-8dd005aafe2f" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_aa08bdc8-7332-418c-9f47-108fdde63e63" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/ACQUISITIONOFSUBSIDIARIESProFormaInformationDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#ACQUISITIONOFSUBSIDIARIESProFormaInformationDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/ACQUISITIONOFSUBSIDIARIESProFormaInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_b8fcf122-4d38-4498-98ec-148c864c302c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_40632bcf-2072-4a1b-8a90-2c48840fe170" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_b8fcf122-4d38-4498-98ec-148c864c302c" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_40632bcf-2072-4a1b-8a90-2c48840fe170" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_26d2a384-b076-4170-9d2e-cdd99e49ecb2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_40632bcf-2072-4a1b-8a90-2c48840fe170" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_26d2a384-b076-4170-9d2e-cdd99e49ecb2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_26d2a384-b076-4170-9d2e-cdd99e49ecb2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_26d2a384-b076-4170-9d2e-cdd99e49ecb2" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_26d2a384-b076-4170-9d2e-cdd99e49ecb2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_fe0b27e6-930e-4a4e-8376-3b30b95bd2d9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_26d2a384-b076-4170-9d2e-cdd99e49ecb2" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_fe0b27e6-930e-4a4e-8376-3b30b95bd2d9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_PowerGasMember_ccd608a6-01e4-43c2-b149-9362fbe56823" xlink:href="fip-20260331.xsd#fip_PowerGasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_fe0b27e6-930e-4a4e-8376-3b30b95bd2d9" xlink:to="loc_fip_PowerGasMember_ccd608a6-01e4-43c2-b149-9362fbe56823" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionsProFormaRevenue_79adc195-9373-468b-ae03-401e7a977243" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionsProFormaRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_b8fcf122-4d38-4498-98ec-148c864c302c" xlink:to="loc_us-gaap_BusinessAcquisitionsProFormaRevenue_79adc195-9373-468b-ae03-401e7a977243" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_4631db4f-2ba8-48f6-9d7e-59c6806f240c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_b8fcf122-4d38-4498-98ec-148c864c302c" xlink:to="loc_us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_4631db4f-2ba8-48f6-9d7e-59c6806f240c" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/LEASINGEQUIPMENTNETDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#LEASINGEQUIPMENTNETDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/LEASINGEQUIPMENTNETDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalLeasedAssetsLineItems_eb40f246-7f57-493a-84df-86c5edc2e48a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CapitalLeasedAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseByMajorPropertyClassTable_ad145129-b370-4866-a34a-2fae34a9f268" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertySubjectToOrAvailableForOperatingLeaseByMajorPropertyClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_CapitalLeasedAssetsLineItems_eb40f246-7f57-493a-84df-86c5edc2e48a" xlink:to="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseByMajorPropertyClassTable_ad145129-b370-4866-a34a-2fae34a9f268" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_6e1a8dca-9c81-42b0-bb3b-62a6e6a8cb39" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseByMajorPropertyClassTable_ad145129-b370-4866-a34a-2fae34a9f268" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_6e1a8dca-9c81-42b0-bb3b-62a6e6a8cb39" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_6e1a8dca-9c81-42b0-bb3b-62a6e6a8cb39_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_6e1a8dca-9c81-42b0-bb3b-62a6e6a8cb39" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_6e1a8dca-9c81-42b0-bb3b-62a6e6a8cb39_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_c81158af-3d99-42de-b02d-fa726175fb16" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_6e1a8dca-9c81-42b0-bb3b-62a6e6a8cb39" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_c81158af-3d99-42de-b02d-fa726175fb16" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_LeasingEquipmentMember_f226cc42-db90-46b8-8a7d-4ac1859c5f3b" xlink:href="fip-20260331.xsd#fip_LeasingEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_c81158af-3d99-42de-b02d-fa726175fb16" xlink:to="loc_fip_LeasingEquipmentMember_f226cc42-db90-46b8-8a7d-4ac1859c5f3b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_ad8aace6-0c73-447f-bfc1-c78c979bb859" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MajorCustomersAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseByMajorPropertyClassTable_ad145129-b370-4866-a34a-2fae34a9f268" xlink:to="loc_srt_MajorCustomersAxis_ad8aace6-0c73-447f-bfc1-c78c979bb859" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_ad8aace6-0c73-447f-bfc1-c78c979bb859_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_ad8aace6-0c73-447f-bfc1-c78c979bb859" xlink:to="loc_srt_NameOfMajorCustomerDomain_ad8aace6-0c73-447f-bfc1-c78c979bb859_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_3a75a8b4-17e2-46eb-abbf-84382a4c7932" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_ad8aace6-0c73-447f-bfc1-c78c979bb859" xlink:to="loc_srt_NameOfMajorCustomerDomain_3a75a8b4-17e2-46eb-abbf-84382a4c7932" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_JeffersonTerminalMember_01c4a522-8fba-4791-8927-49f06c0a3027" xlink:href="fip-20260331.xsd#fip_JeffersonTerminalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_3a75a8b4-17e2-46eb-abbf-84382a4c7932" xlink:to="loc_fip_JeffersonTerminalMember_01c4a522-8fba-4791-8927-49f06c0a3027" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_PropertyPlantAndEquipmentLeasingEquipmentGross_ec40668f-d86e-4305-9efd-eb1bcf9034a9" xlink:href="fip-20260331.xsd#fip_PropertyPlantAndEquipmentLeasingEquipmentGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalLeasedAssetsLineItems_eb40f246-7f57-493a-84df-86c5edc2e48a" xlink:to="loc_fip_PropertyPlantAndEquipmentLeasingEquipmentGross_ec40668f-d86e-4305-9efd-eb1bcf9034a9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipmentLeasingEquipment_9ef7b0e3-4a42-437e-b59c-c65567c6a277" xlink:href="fip-20260331.xsd#fip_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipmentLeasingEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalLeasedAssetsLineItems_eb40f246-7f57-493a-84df-86c5edc2e48a" xlink:to="loc_fip_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipmentLeasingEquipment_9ef7b0e3-4a42-437e-b59c-c65567c6a277" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_PropertyPlantAndEquipmentLeasingEquipment_efd948da-8db2-431d-be91-d104443c837c" xlink:href="fip-20260331.xsd#fip_PropertyPlantAndEquipmentLeasingEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalLeasedAssetsLineItems_eb40f246-7f57-493a-84df-86c5edc2e48a" xlink:to="loc_fip_PropertyPlantAndEquipmentLeasingEquipment_efd948da-8db2-431d-be91-d104443c837c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Depreciation_30803b1e-d0cd-447e-aaf7-e46e9b88ca1d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Depreciation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalLeasedAssetsLineItems_eb40f246-7f57-493a-84df-86c5edc2e48a" xlink:to="loc_us-gaap_Depreciation_30803b1e-d0cd-447e-aaf7-e46e9b88ca1d" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/PROPERTYPLANTANDEQUIPMENTNETDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#PROPERTYPLANTANDEQUIPMENTNETDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/PROPERTYPLANTANDEQUIPMENTNETDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_202a47b5-f25c-4389-aa56-09723b4093fe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_1c4e2ba8-57a1-4628-afc8-12ab6c96db1f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_202a47b5-f25c-4389-aa56-09723b4093fe" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_1c4e2ba8-57a1-4628-afc8-12ab6c96db1f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_5135203e-9f14-4105-8ea7-ed4feed62c7e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_1c4e2ba8-57a1-4628-afc8-12ab6c96db1f" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_5135203e-9f14-4105-8ea7-ed4feed62c7e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_5135203e-9f14-4105-8ea7-ed4feed62c7e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_5135203e-9f14-4105-8ea7-ed4feed62c7e" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_5135203e-9f14-4105-8ea7-ed4feed62c7e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9e060e38-eec4-4b50-bda0-28a1c1ddaeaf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_5135203e-9f14-4105-8ea7-ed4feed62c7e" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9e060e38-eec4-4b50-bda0-28a1c1ddaeaf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LandAndLandImprovementsMember_2fb71e72-bd30-4539-835a-cd4197c0fb6e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LandAndLandImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9e060e38-eec4-4b50-bda0-28a1c1ddaeaf" xlink:to="loc_us-gaap_LandAndLandImprovementsMember_2fb71e72-bd30-4539-835a-cd4197c0fb6e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BuildingAndBuildingImprovementsMember_b2cd55eb-f405-4b2e-a77c-5bf331f82245" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BuildingAndBuildingImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9e060e38-eec4-4b50-bda0-28a1c1ddaeaf" xlink:to="loc_us-gaap_BuildingAndBuildingImprovementsMember_b2cd55eb-f405-4b2e-a77c-5bf331f82245" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_BridgesAndTunnelsMember_66df8143-bbb6-4485-8f61-9a910abb9472" xlink:href="fip-20260331.xsd#fip_BridgesAndTunnelsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9e060e38-eec4-4b50-bda0-28a1c1ddaeaf" xlink:to="loc_fip_BridgesAndTunnelsMember_66df8143-bbb6-4485-8f61-9a910abb9472" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EnergyEquipmentMember_09857656-ae87-4d8c-af86-85198da76139" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EnergyEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9e060e38-eec4-4b50-bda0-28a1c1ddaeaf" xlink:to="loc_us-gaap_EnergyEquipmentMember_09857656-ae87-4d8c-af86-85198da76139" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OilAndGasPropertiesMember_3c48e71d-69d2-4a27-ba85-1b1bd44d446f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OilAndGasPropertiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9e060e38-eec4-4b50-bda0-28a1c1ddaeaf" xlink:to="loc_us-gaap_OilAndGasPropertiesMember_3c48e71d-69d2-4a27-ba85-1b1bd44d446f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_UnprovedOilAndGasMember_019cbfa0-2ead-7d22-a889-c80505193e83" xlink:href="fip-20260331.xsd#fip_UnprovedOilAndGasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9e060e38-eec4-4b50-bda0-28a1c1ddaeaf" xlink:to="loc_fip_UnprovedOilAndGasMember_019cbfa0-2ead-7d22-a889-c80505193e83" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NaturalGasProcessingPlantMember_dba84e65-e27c-4c36-8b97-a08e2c33ee8a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NaturalGasProcessingPlantMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9e060e38-eec4-4b50-bda0-28a1c1ddaeaf" xlink:to="loc_us-gaap_NaturalGasProcessingPlantMember_dba84e65-e27c-4c36-8b97-a08e2c33ee8a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_RailroadTrackandRelatedAssetsMember_6e1d7252-c0fb-4b83-977e-47d8ee7d0340" xlink:href="fip-20260331.xsd#fip_RailroadTrackandRelatedAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9e060e38-eec4-4b50-bda0-28a1c1ddaeaf" xlink:to="loc_fip_RailroadTrackandRelatedAssetsMember_6e1d7252-c0fb-4b83-977e-47d8ee7d0340" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_RailroadEquipmentMember_cc551b45-9fa0-42b1-9cd4-02f7245d4078" xlink:href="fip-20260331.xsd#fip_RailroadEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9e060e38-eec4-4b50-bda0-28a1c1ddaeaf" xlink:to="loc_fip_RailroadEquipmentMember_cc551b45-9fa0-42b1-9cd4-02f7245d4078" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_RailcarsandLocomotivesMember_5de9e091-2787-4a10-be97-ee44d0765505" xlink:href="fip-20260331.xsd#fip_RailcarsandLocomotivesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9e060e38-eec4-4b50-bda0-28a1c1ddaeaf" xlink:to="loc_fip_RailcarsandLocomotivesMember_5de9e091-2787-4a10-be97-ee44d0765505" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_ComputerHardwareandSoftwareMember_017f4d98-f3ba-4e53-9c96-3f3bc692369b" xlink:href="fip-20260331.xsd#fip_ComputerHardwareandSoftwareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9e060e38-eec4-4b50-bda0-28a1c1ddaeaf" xlink:to="loc_fip_ComputerHardwareandSoftwareMember_017f4d98-f3ba-4e53-9c96-3f3bc692369b" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_999a64ca-91c5-4da1-9f5a-5643c900f8b3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FurnitureAndFixturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9e060e38-eec4-4b50-bda0-28a1c1ddaeaf" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_999a64ca-91c5-4da1-9f5a-5643c900f8b3" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionInProgressMember_36acea6c-6d1d-4830-8cfa-aead2cc2f0fc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConstructionInProgressMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9e060e38-eec4-4b50-bda0-28a1c1ddaeaf" xlink:to="loc_us-gaap_ConstructionInProgressMember_36acea6c-6d1d-4830-8cfa-aead2cc2f0fc" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VehiclesMember_c18c90b8-3040-4c25-aee6-df16ec184277" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VehiclesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9e060e38-eec4-4b50-bda0-28a1c1ddaeaf" xlink:to="loc_us-gaap_VehiclesMember_c18c90b8-3040-4c25-aee6-df16ec184277" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_e92ba50d-beb6-4510-a14c-0e84d3c2d6f1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_202a47b5-f25c-4389-aa56-09723b4093fe" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_e92ba50d-beb6-4510-a14c-0e84d3c2d6f1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_2c3b4292-f1f7-438c-8c75-b9dce6c56251" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_202a47b5-f25c-4389-aa56-09723b4093fe" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_2c3b4292-f1f7-438c-8c75-b9dce6c56251" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_63f4ca34-3039-4df1-a42e-4d0b8c5377e0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_202a47b5-f25c-4389-aa56-09723b4093fe" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_63f4ca34-3039-4df1-a42e-4d0b8c5377e0" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/INVESTMENTSOwnershipCarryingValuesDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#INVESTMENTSOwnershipCarryingValuesDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/INVESTMENTSOwnershipCarryingValuesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_e3a6bf69-cfcb-4e19-8b9b-bc2ebc6d999c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_42de66cd-4ff6-4402-9fe9-3457e874eda7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_e3a6bf69-cfcb-4e19-8b9b-bc2ebc6d999c" xlink:to="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_42de66cd-4ff6-4402-9fe9-3457e874eda7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_5984a512-128b-418e-82e4-7660f971ea76" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_42de66cd-4ff6-4402-9fe9-3457e874eda7" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_5984a512-128b-418e-82e4-7660f971ea76" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_5984a512-128b-418e-82e4-7660f971ea76_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_5984a512-128b-418e-82e4-7660f971ea76" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_5984a512-128b-418e-82e4-7660f971ea76_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_3f479b5c-f944-4fca-9cf6-f15571137883" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_5984a512-128b-418e-82e4-7660f971ea76" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_3f479b5c-f944-4fca-9cf6-f15571137883" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_IntermodalFinanceILtdMember_657d2472-5ebe-48e0-b493-6aae9f9ea47b" xlink:href="fip-20260331.xsd#fip_IntermodalFinanceILtdMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_3f479b5c-f944-4fca-9cf6-f15571137883" xlink:to="loc_fip_IntermodalFinanceILtdMember_657d2472-5ebe-48e0-b493-6aae9f9ea47b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_GMFTAIHoldcoLLCMember_65198d9c-5c6c-499e-915c-f4924e88947d" xlink:href="fip-20260331.xsd#fip_GMFTAIHoldcoLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_3f479b5c-f944-4fca-9cf6-f15571137883" xlink:to="loc_fip_GMFTAIHoldcoLLCMember_65198d9c-5c6c-499e-915c-f4924e88947d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_PyroplastEnergyLTDMember_019c9195-18fa-7890-b111-245afaf8445c" xlink:href="fip-20260331.xsd#fip_PyroplastEnergyLTDMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_3f479b5c-f944-4fca-9cf6-f15571137883" xlink:to="loc_fip_PyroplastEnergyLTDMember_019c9195-18fa-7890-b111-245afaf8445c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_317fd6d4-d8ef-48ad-b990-0a7211531567" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_e3a6bf69-cfcb-4e19-8b9b-bc2ebc6d999c" xlink:to="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_317fd6d4-d8ef-48ad-b990-0a7211531567" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestments_ab561871-c2a9-41ca-9cd0-efb4f21ce4e0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_e3a6bf69-cfcb-4e19-8b9b-bc2ebc6d999c" xlink:to="loc_us-gaap_EquityMethodInvestments_ab561871-c2a9-41ca-9cd0-efb4f21ce4e0" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/INVESTMENTSShareofEquityofIncomeLossDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#INVESTMENTSShareofEquityofIncomeLossDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/INVESTMENTSShareofEquityofIncomeLossDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_d53bf853-6f86-4a2b-bdc8-cf0e199a29c9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_ee861166-9039-41f9-ab8e-420fc942c628" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_d53bf853-6f86-4a2b-bdc8-cf0e199a29c9" xlink:to="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_ee861166-9039-41f9-ab8e-420fc942c628" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_3791ce48-0f8f-46b0-b6ea-de50411f38c2" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_ee861166-9039-41f9-ab8e-420fc942c628" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_3791ce48-0f8f-46b0-b6ea-de50411f38c2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_3791ce48-0f8f-46b0-b6ea-de50411f38c2_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_3791ce48-0f8f-46b0-b6ea-de50411f38c2" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_3791ce48-0f8f-46b0-b6ea-de50411f38c2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_37704441-80b3-4c1b-8f7a-6499bea2dfb0" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_3791ce48-0f8f-46b0-b6ea-de50411f38c2" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_37704441-80b3-4c1b-8f7a-6499bea2dfb0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_IntermodalFinanceILtdMember_d1fdde57-7092-4d94-aa0e-7744d52c3645" xlink:href="fip-20260331.xsd#fip_IntermodalFinanceILtdMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_37704441-80b3-4c1b-8f7a-6499bea2dfb0" xlink:to="loc_fip_IntermodalFinanceILtdMember_d1fdde57-7092-4d94-aa0e-7744d52c3645" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_PowerGasMember_9e1c57d2-32a9-484a-b58a-bafe24325bff" xlink:href="fip-20260331.xsd#fip_PowerGasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_37704441-80b3-4c1b-8f7a-6499bea2dfb0" xlink:to="loc_fip_PowerGasMember_9e1c57d2-32a9-484a-b58a-bafe24325bff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_GMFTAIHoldcoLLCMember_1eb70fce-b997-4841-ba2d-37291cc2b8ab" xlink:href="fip-20260331.xsd#fip_GMFTAIHoldcoLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_37704441-80b3-4c1b-8f7a-6499bea2dfb0" xlink:to="loc_fip_GMFTAIHoldcoLLCMember_1eb70fce-b997-4841-ba2d-37291cc2b8ab" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_CleanPlanetEnergyUSALLCMember_a45c67b3-951c-4567-8f26-e5a56e309acb" xlink:href="fip-20260331.xsd#fip_CleanPlanetEnergyUSALLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_37704441-80b3-4c1b-8f7a-6499bea2dfb0" xlink:to="loc_fip_CleanPlanetEnergyUSALLCMember_a45c67b3-951c-4567-8f26-e5a56e309acb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_PyroplastEnergyLTDMember_019c9195-70fb-7376-9c40-a733df1eccfd" xlink:href="fip-20260331.xsd#fip_PyroplastEnergyLTDMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_37704441-80b3-4c1b-8f7a-6499bea2dfb0" xlink:to="loc_fip_PyroplastEnergyLTDMember_019c9195-70fb-7376-9c40-a733df1eccfd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_LongRidgeWestVirginiaLLCMember_019df319-82a4-7577-a91e-340d5b3d34c4" xlink:href="fip-20260331.xsd#fip_LongRidgeWestVirginiaLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_37704441-80b3-4c1b-8f7a-6499bea2dfb0" xlink:to="loc_fip_LongRidgeWestVirginiaLLCMember_019df319-82a4-7577-a91e-340d5b3d34c4" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_LongRidgeEnergyPowerLLCMember_019df319-b157-789f-87b0-d4ea65543063" xlink:href="fip-20260331.xsd#fip_LongRidgeEnergyPowerLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_37704441-80b3-4c1b-8f7a-6499bea2dfb0" xlink:to="loc_fip_LongRidgeEnergyPowerLLCMember_019df319-b157-789f-87b0-d4ea65543063" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromEquityMethodInvestments_af2b9e57-44fd-464f-a9cd-4b58cb78c028" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromEquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_d53bf853-6f86-4a2b-bdc8-cf0e199a29c9" xlink:to="loc_us-gaap_IncomeLossFromEquityMethodInvestments_af2b9e57-44fd-464f-a9cd-4b58cb78c028" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/INVESTMENTSNarrativeDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#INVESTMENTSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/INVESTMENTSNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019de4bf-502e-75e1-bd95-ebdf3cc213e4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_019de4bf-502e-7225-9d34-54bf9e20c840" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019de4bf-502e-75e1-bd95-ebdf3cc213e4" xlink:to="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_019de4bf-502e-7225-9d34-54bf9e20c840" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019de4bf-502e-7374-ab66-969516fd1e50" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_019de4bf-502e-7225-9d34-54bf9e20c840" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019de4bf-502e-7374-ab66-969516fd1e50" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_019de4bf-502e-7374-ab66-969516fd1e50_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019de4bf-502e-7374-ab66-969516fd1e50" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_019de4bf-502e-7374-ab66-969516fd1e50_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_019de4bf-502e-78b7-8d31-f8601938c474" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019de4bf-502e-7374-ab66-969516fd1e50" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_019de4bf-502e-78b7-8d31-f8601938c474" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_TimberHPMadisonLLCMember_019de4bf-502e-7c91-a22b-eced94be7bee" xlink:href="fip-20260331.xsd#fip_TimberHPMadisonLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_019de4bf-502e-78b7-8d31-f8601938c474" xlink:to="loc_fip_TimberHPMadisonLLCMember_019de4bf-502e-7c91-a22b-eced94be7bee" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireOtherInvestments_019de4bf-502e-7dac-b0df-17125b6052ae" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquireOtherInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019de4bf-502e-75e1-bd95-ebdf3cc213e4" xlink:to="loc_us-gaap_PaymentsToAcquireOtherInvestments_019de4bf-502e-7dac-b0df-17125b6052ae" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentInterestRate_019de4bf-502e-7651-b1d6-dcd05c0dcccd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019de4bf-502e-75e1-bd95-ebdf3cc213e4" xlink:to="loc_us-gaap_InvestmentInterestRate_019de4bf-502e-7651-b1d6-dcd05c0dcccd" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/INTANGIBLEASSETSNETSummarizedIntangibleAssetsandLiabilitiesDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#INTANGIBLEASSETSNETSummarizedIntangibleAssetsandLiabilitiesDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/INTANGIBLEASSETSNETSummarizedIntangibleAssetsandLiabilitiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_f90565dc-6262-45da-a5e8-6faa986805c6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_8df66bdf-c729-43cb-af83-4e07ec14a514" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_f90565dc-6262-45da-a5e8-6faa986805c6" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_8df66bdf-c729-43cb-af83-4e07ec14a514" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_6fc9e03a-9ffe-4da9-b0bd-c4754858dc55" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_8df66bdf-c729-43cb-af83-4e07ec14a514" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_6fc9e03a-9ffe-4da9-b0bd-c4754858dc55" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_6fc9e03a-9ffe-4da9-b0bd-c4754858dc55_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_6fc9e03a-9ffe-4da9-b0bd-c4754858dc55" xlink:to="loc_us-gaap_SegmentDomain_6fc9e03a-9ffe-4da9-b0bd-c4754858dc55_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_5002d193-75d1-44d3-a1b0-71ccb186c1cf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_6fc9e03a-9ffe-4da9-b0bd-c4754858dc55" xlink:to="loc_us-gaap_SegmentDomain_5002d193-75d1-44d3-a1b0-71ccb186c1cf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_PowerGasMember_c078d7aa-dc01-458a-8653-e2348c1893d0" xlink:href="fip-20260331.xsd#fip_PowerGasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_5002d193-75d1-44d3-a1b0-71ccb186c1cf" xlink:to="loc_fip_PowerGasMember_c078d7aa-dc01-458a-8653-e2348c1893d0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_RailroadMember_d65b5d55-a31a-46fb-aace-d116796febf5" xlink:href="fip-20260331.xsd#fip_RailroadMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_5002d193-75d1-44d3-a1b0-71ccb186c1cf" xlink:to="loc_fip_RailroadMember_d65b5d55-a31a-46fb-aace-d116796febf5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_49c725e3-f9d7-417d-bdf5-1feb68512a4e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsNetAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_f90565dc-6262-45da-a5e8-6faa986805c6" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_49c725e3-f9d7-417d-bdf5-1feb68512a4e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_dd4d49cf-d7bd-4153-831c-c0139075ea79" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_49c725e3-f9d7-417d-bdf5-1feb68512a4e" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_dd4d49cf-d7bd-4153-831c-c0139075ea79" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_1ff77454-7a41-48be-8b9b-56a9d0d1788c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_49c725e3-f9d7-417d-bdf5-1feb68512a4e" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_1ff77454-7a41-48be-8b9b-56a9d0d1788c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_96da21b2-14e5-425a-b008-13454d1eef3d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_49c725e3-f9d7-417d-bdf5-1feb68512a4e" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_96da21b2-14e5-425a-b008-13454d1eef3d" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/INTANGIBLEASSETSNETIntangibleLiabilitiesAmortizationDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#INTANGIBLEASSETSNETIntangibleLiabilitiesAmortizationDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/INTANGIBLEASSETSNETIntangibleLiabilitiesAmortizationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_9c3be50b-197f-4fe0-a957-9c8b30203fc3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_37ba9728-b963-4006-8bc6-df7078cb91fa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_9c3be50b-197f-4fe0-a957-9c8b30203fc3" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_37ba9728-b963-4006-8bc6-df7078cb91fa" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_197083e8-49aa-47b4-93e3-61a00d60a698" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_37ba9728-b963-4006-8bc6-df7078cb91fa" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_197083e8-49aa-47b4-93e3-61a00d60a698" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_197083e8-49aa-47b4-93e3-61a00d60a698_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_197083e8-49aa-47b4-93e3-61a00d60a698" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_197083e8-49aa-47b4-93e3-61a00d60a698_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_c0706f81-f880-4712-ae84-04bf2aff3604" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_197083e8-49aa-47b4-93e3-61a00d60a698" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_c0706f81-f880-4712-ae84-04bf2aff3604" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_DepreciationandAmortizationMember_f664d2c4-ffc4-466c-989c-5c0f20a8555c" xlink:href="fip-20260331.xsd#fip_DepreciationandAmortizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_c0706f81-f880-4712-ae84-04bf2aff3604" xlink:to="loc_fip_DepreciationandAmortizationMember_f664d2c4-ffc4-466c-989c-5c0f20a8555c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_14c16ece-b92a-4224-89c9-3f013257f001" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_9c3be50b-197f-4fe0-a957-9c8b30203fc3" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_14c16ece-b92a-4224-89c9-3f013257f001" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/DEBTNETScheduleofDebtDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#DEBTNETScheduleofDebtDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/DEBTNETScheduleofDebtDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019de4c1-445e-75fd-b2d0-ff75f84fa7c9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019de4c1-445e-72e7-a449-e36037cefb1e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019de4c1-445e-75fd-b2d0-ff75f84fa7c9" xlink:to="loc_us-gaap_DebtInstrumentTable_019de4c1-445e-72e7-a449-e36037cefb1e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019de4c1-445e-7978-995f-240b196366b5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019de4c1-445e-72e7-a449-e36037cefb1e" xlink:to="loc_us-gaap_DebtInstrumentAxis_019de4c1-445e-7978-995f-240b196366b5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7978-995f-240b196366b5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019de4c1-445e-7978-995f-240b196366b5" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7978-995f-240b196366b5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7a01-b7ac-4c6d82dc5a7f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019de4c1-445e-7978-995f-240b196366b5" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7a01-b7ac-4c6d82dc5a7f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_DRPDBTermLoanMember_019de4c1-445e-722b-b645-b78059957550" xlink:href="fip-20260331.xsd#fip_DRPDBTermLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7a01-b7ac-4c6d82dc5a7f" xlink:to="loc_fip_DRPDBTermLoanMember_019de4c1-445e-722b-b645-b78059957550" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_CorporateBridgeLoanCreditAgreement1.25BMember_019de4c1-445e-7e3e-aa87-c93f0b9e14ab" xlink:href="fip-20260331.xsd#fip_CorporateBridgeLoanCreditAgreement1.25BMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7a01-b7ac-4c6d82dc5a7f" xlink:to="loc_fip_CorporateBridgeLoanCreditAgreement1.25BMember_019de4c1-445e-7e3e-aa87-c93f0b9e14ab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_CorporateTermLoanCreditAgreement1.35BMember_019de4c1-445e-75f0-966c-27ca840f0b87" xlink:href="fip-20260331.xsd#fip_CorporateTermLoanCreditAgreement1.35BMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7a01-b7ac-4c6d82dc5a7f" xlink:to="loc_fip_CorporateTermLoanCreditAgreement1.35BMember_019de4c1-445e-75f0-966c-27ca840f0b87" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_EB5LoanAgreementMember_019de4c1-445e-793c-8382-01094f0e25e4" xlink:href="fip-20260331.xsd#fip_EB5LoanAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7a01-b7ac-4c6d82dc5a7f" xlink:to="loc_fip_EB5LoanAgreementMember_019de4c1-445e-793c-8382-01094f0e25e4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_JeffersonCreditAgreementJune2025Member_019de4c1-445e-7c0a-a384-282adc291418" xlink:href="fip-20260331.xsd#fip_JeffersonCreditAgreementJune2025Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7a01-b7ac-4c6d82dc5a7f" xlink:to="loc_fip_JeffersonCreditAgreementJune2025Member_019de4c1-445e-7c0a-a384-282adc291418" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_RailCoRevolverMember_019de4c1-445e-7091-8884-f85c837fc96a" xlink:href="fip-20260331.xsd#fip_RailCoRevolverMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7a01-b7ac-4c6d82dc5a7f" xlink:to="loc_fip_RailCoRevolverMember_019de4c1-445e-7091-8884-f85c837fc96a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_LongRidgeAcquiomLoanMember_019de4c1-445e-7974-9baa-a8c712183fb6" xlink:href="fip-20260331.xsd#fip_LongRidgeAcquiomLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7a01-b7ac-4c6d82dc5a7f" xlink:to="loc_fip_LongRidgeAcquiomLoanMember_019de4c1-445e-7974-9baa-a8c712183fb6" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_LongRidgeGCMPrommissoryNoteMember_019de4c1-445e-7f79-9baf-38b7d518d317" xlink:href="fip-20260331.xsd#fip_LongRidgeGCMPrommissoryNoteMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7a01-b7ac-4c6d82dc5a7f" xlink:to="loc_fip_LongRidgeGCMPrommissoryNoteMember_019de4c1-445e-7f79-9baf-38b7d518d317" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_LongRidgeCanamLoanMember_019de4c1-445e-7b16-8773-87819aa698ae" xlink:href="fip-20260331.xsd#fip_LongRidgeCanamLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7a01-b7ac-4c6d82dc5a7f" xlink:to="loc_fip_LongRidgeCanamLoanMember_019de4c1-445e-7b16-8773-87819aa698ae" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_LongRidgeCreditAgreementMember_019de4c1-445e-7ffe-a9a5-5e29722231fb" xlink:href="fip-20260331.xsd#fip_LongRidgeCreditAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7a01-b7ac-4c6d82dc5a7f" xlink:to="loc_fip_LongRidgeCreditAgreementMember_019de4c1-445e-7ffe-a9a5-5e29722231fb" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_Series2020BondsDue2050Member_019de4c1-445e-72d1-964c-de393517eeaa" xlink:href="fip-20260331.xsd#fip_Series2020BondsDue2050Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7a01-b7ac-4c6d82dc5a7f" xlink:to="loc_fip_Series2020BondsDue2050Member_019de4c1-445e-72d1-964c-de393517eeaa" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_Series2020BondsDue2035Member_019de4c1-445e-7b7c-9a46-f64e1027ebb5" xlink:href="fip-20260331.xsd#fip_Series2020BondsDue2035Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7a01-b7ac-4c6d82dc5a7f" xlink:to="loc_fip_Series2020BondsDue2035Member_019de4c1-445e-7b7c-9a46-f64e1027ebb5" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_Series2020BondsMember_019de4c1-445e-7397-8ff2-40f8fc855442" xlink:href="fip-20260331.xsd#fip_Series2020BondsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7a01-b7ac-4c6d82dc5a7f" xlink:to="loc_fip_Series2020BondsMember_019de4c1-445e-7397-8ff2-40f8fc855442" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_Series2021ABondsDue2050Member_019de4c1-445e-7bf4-b957-4e5d65973930" xlink:href="fip-20260331.xsd#fip_Series2021ABondsDue2050Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7a01-b7ac-4c6d82dc5a7f" xlink:to="loc_fip_Series2021ABondsDue2050Member_019de4c1-445e-7bf4-b957-4e5d65973930" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_Series2021ABondsDue2026Through2041Member_019de4c1-445e-7ebd-a2c5-fa4f673c2943" xlink:href="fip-20260331.xsd#fip_Series2021ABondsDue2026Through2041Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7a01-b7ac-4c6d82dc5a7f" xlink:to="loc_fip_Series2021ABondsDue2026Through2041Member_019de4c1-445e-7ebd-a2c5-fa4f673c2943" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_Series2021BBondsMember_019de4c1-445e-71a8-929c-14e857f60b0c" xlink:href="fip-20260331.xsd#fip_Series2021BBondsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7a01-b7ac-4c6d82dc5a7f" xlink:to="loc_fip_Series2021BBondsMember_019de4c1-445e-71a8-929c-14e857f60b0c" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_Series2021BondsMember_019de4c1-445e-7e54-9dcb-acdf2973fad8" xlink:href="fip-20260331.xsd#fip_Series2021BondsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7a01-b7ac-4c6d82dc5a7f" xlink:to="loc_fip_Series2021BondsMember_019de4c1-445e-7e54-9dcb-acdf2973fad8" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_Series2024ABondsDue2039Through2044Member_019de4c1-445e-7221-b6b5-6ef6e2086020" xlink:href="fip-20260331.xsd#fip_Series2024ABondsDue2039Through2044Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7a01-b7ac-4c6d82dc5a7f" xlink:to="loc_fip_Series2024ABondsDue2039Through2044Member_019de4c1-445e-7221-b6b5-6ef6e2086020" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_Series2024ABondsDue2044Member_019de4c1-445e-79e1-bf6e-170db8df5424" xlink:href="fip-20260331.xsd#fip_Series2024ABondsDue2044Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7a01-b7ac-4c6d82dc5a7f" xlink:to="loc_fip_Series2024ABondsDue2044Member_019de4c1-445e-79e1-bf6e-170db8df5424" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_Series2024BBondsDue2026Member_019de4c1-445e-71a0-89fa-5b3e5e3e7238" xlink:href="fip-20260331.xsd#fip_Series2024BBondsDue2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7a01-b7ac-4c6d82dc5a7f" xlink:to="loc_fip_Series2024BBondsDue2026Member_019de4c1-445e-71a0-89fa-5b3e5e3e7238" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_Series2024BondsMember_019de4c1-445e-7b9b-9797-615335cb7f55" xlink:href="fip-20260331.xsd#fip_Series2024BondsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7a01-b7ac-4c6d82dc5a7f" xlink:to="loc_fip_Series2024BondsMember_019de4c1-445e-7b9b-9797-615335cb7f55" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_Series2025BondsDue2035Member_019de4c1-445e-71db-9707-07c59645f68f" xlink:href="fip-20260331.xsd#fip_Series2025BondsDue2035Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7a01-b7ac-4c6d82dc5a7f" xlink:to="loc_fip_Series2025BondsDue2035Member_019de4c1-445e-71db-9707-07c59645f68f" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_Series2025BondsDue2045Member_019de4c1-445e-7ea5-adff-072b7f21a6c5" xlink:href="fip-20260331.xsd#fip_Series2025BondsDue2045Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7a01-b7ac-4c6d82dc5a7f" xlink:to="loc_fip_Series2025BondsDue2045Member_019de4c1-445e-7ea5-adff-072b7f21a6c5" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_Series2025BondsMember_019de4c1-445e-792d-acf6-fa95713d0747" xlink:href="fip-20260331.xsd#fip_Series2025BondsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7a01-b7ac-4c6d82dc5a7f" xlink:to="loc_fip_Series2025BondsMember_019de4c1-445e-792d-acf6-fa95713d0747" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_SeniorNotesDue2032Member_019de4c1-445e-7f69-8c65-2d63c67801fb" xlink:href="fip-20260331.xsd#fip_SeniorNotesDue2032Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c1-445e-7a01-b7ac-4c6d82dc5a7f" xlink:to="loc_fip_SeniorNotesDue2032Member_019de4c1-445e-7f69-8c65-2d63c67801fb" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019de4c1-445e-7041-b386-55f11f519872" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019de4c1-445e-72e7-a449-e36037cefb1e" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019de4c1-445e-7041-b386-55f11f519872" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019de4c1-445e-7041-b386-55f11f519872_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019de4c1-445e-7041-b386-55f11f519872" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019de4c1-445e-7041-b386-55f11f519872_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019de4c1-445e-7638-bc5e-69a3bd8153b4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019de4c1-445e-7041-b386-55f11f519872" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019de4c1-445e-7638-bc5e-69a3bd8153b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateBondSecuritiesMember_019de4c1-445e-7efa-a3ef-dcc3cc9c5d4b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CorporateBondSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019de4c1-445e-7638-bc5e-69a3bd8153b4" xlink:to="loc_us-gaap_CorporateBondSecuritiesMember_019de4c1-445e-7efa-a3ef-dcc3cc9c5d4b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansPayableMember_019de4c1-445e-72c7-b6d7-6477084a3462" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LoansPayableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019de4c1-445e-7638-bc5e-69a3bd8153b4" xlink:to="loc_us-gaap_LoansPayableMember_019de4c1-445e-72c7-b6d7-6477084a3462" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_019de4c1-445e-796b-b653-691c9dd4e4f2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019de4c1-445e-7638-bc5e-69a3bd8153b4" xlink:to="loc_us-gaap_LineOfCreditMember_019de4c1-445e-796b-b653-691c9dd4e4f2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_019de4c1-445e-75b2-b74d-77e258338eaa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableRateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019de4c1-445e-72e7-a449-e36037cefb1e" xlink:to="loc_us-gaap_VariableRateAxis_019de4c1-445e-75b2-b74d-77e258338eaa" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_019de4c1-445e-75b2-b74d-77e258338eaa_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_019de4c1-445e-75b2-b74d-77e258338eaa" xlink:to="loc_us-gaap_VariableRateDomain_019de4c1-445e-75b2-b74d-77e258338eaa_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_019de4c1-445e-7625-beff-6fd85d506343" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_019de4c1-445e-75b2-b74d-77e258338eaa" xlink:to="loc_us-gaap_VariableRateDomain_019de4c1-445e-7625-beff-6fd85d506343" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EurodollarMember_019de4c1-445e-7bb4-b25a-58bf98b50660" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EurodollarMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_019de4c1-445e-7625-beff-6fd85d506343" xlink:to="loc_us-gaap_EurodollarMember_019de4c1-445e-7bb4-b25a-58bf98b50660" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BaseRateMember_019de4c1-445e-775d-ae3a-2d0e349d8654" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BaseRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_019de4c1-445e-7625-beff-6fd85d506343" xlink:to="loc_us-gaap_BaseRateMember_019de4c1-445e-775d-ae3a-2d0e349d8654" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_019de4c1-445e-74f1-a28b-d3458bfab7a2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019de4c1-445e-72e7-a449-e36037cefb1e" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_019de4c1-445e-74f1-a28b-d3458bfab7a2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019de4c1-445e-74f1-a28b-d3458bfab7a2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019de4c1-445e-74f1-a28b-d3458bfab7a2" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019de4c1-445e-74f1-a28b-d3458bfab7a2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019de4c1-445e-7c2d-bf4a-791309f6d6ec" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019de4c1-445e-74f1-a28b-d3458bfab7a2" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019de4c1-445e-7c2d-bf4a-791309f6d6ec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_LongRidgeCreditAgreementMember_019de4c1-445e-7ee9-9e93-7e13f955ade9" xlink:href="fip-20260331.xsd#fip_LongRidgeCreditAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019de4c1-445e-7c2d-bf4a-791309f6d6ec" xlink:to="loc_fip_LongRidgeCreditAgreementMember_019de4c1-445e-7ee9-9e93-7e13f955ade9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019de4c1-445e-7689-b457-95cfa7a1dfc9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019de4c1-445e-75fd-b2d0-ff75f84fa7c9" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019de4c1-445e-7689-b457-95cfa7a1dfc9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_019de4c1-445e-7b98-99fe-2c53f9ea8320" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019de4c1-445e-75fd-b2d0-ff75f84fa7c9" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_019de4c1-445e-7b98-99fe-2c53f9ea8320" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_019de4c1-445e-7a0f-ada2-ec2197fcb1ca" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019de4c1-445e-75fd-b2d0-ff75f84fa7c9" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_019de4c1-445e-7a0f-ada2-ec2197fcb1ca" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnamortizedDebtIssuanceExpense_019de4c1-445e-717d-9d5b-dcdcd687830e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnamortizedDebtIssuanceExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019de4c1-445e-75fd-b2d0-ff75f84fa7c9" xlink:to="loc_us-gaap_UnamortizedDebtIssuanceExpense_019de4c1-445e-717d-9d5b-dcdcd687830e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_019de4c1-445e-7215-95f8-bee0c9190daa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019de4c1-445e-75fd-b2d0-ff75f84fa7c9" xlink:to="loc_us-gaap_LongTermDebt_019de4c1-445e-7215-95f8-bee0c9190daa" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_LongTermDebtCurrentMaturitiesGross_019de4c1-445e-7954-98ed-9230d4e97042" xlink:href="fip-20260331.xsd#fip_LongTermDebtCurrentMaturitiesGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019de4c1-445e-75fd-b2d0-ff75f84fa7c9" xlink:to="loc_fip_LongTermDebtCurrentMaturitiesGross_019de4c1-445e-7954-98ed-9230d4e97042" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_UnamortizedDebtIssuanceCostsPortionAttributableToLongTermDebtCurrentMaturities_019de4c1-445e-763a-a7b1-6c5509e34dc7" xlink:href="fip-20260331.xsd#fip_UnamortizedDebtIssuanceCostsPortionAttributableToLongTermDebtCurrentMaturities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019de4c1-445e-75fd-b2d0-ff75f84fa7c9" xlink:to="loc_fip_UnamortizedDebtIssuanceCostsPortionAttributableToLongTermDebtCurrentMaturities_019de4c1-445e-763a-a7b1-6c5509e34dc7" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent_019de4c1-445e-7881-8bca-ff6e07835448" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019de4c1-445e-75fd-b2d0-ff75f84fa7c9" xlink:to="loc_us-gaap_LongTermDebtCurrent_019de4c1-445e-7881-8bca-ff6e07835448" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscount_019de4c1-6ae6-75f7-a9d6-de2fd0d3f0dd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentUnamortizedDiscount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019de4c1-445e-75fd-b2d0-ff75f84fa7c9" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscount_019de4c1-6ae6-75f7-a9d6-de2fd0d3f0dd" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/DEBTNETNarrativeDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#DEBTNETNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/DEBTNETNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019de4c0-e25c-7d6b-83cb-e52d6a31add9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019de4c0-e25c-7443-b185-400d51adbacd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019de4c0-e25c-7d6b-83cb-e52d6a31add9" xlink:to="loc_us-gaap_DebtInstrumentTable_019de4c0-e25c-7443-b185-400d51adbacd" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019de4c0-fe79-7c59-825a-cf1e7a39abcb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019de4c0-e25c-7443-b185-400d51adbacd" xlink:to="loc_us-gaap_DebtInstrumentAxis_019de4c0-fe79-7c59-825a-cf1e7a39abcb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019de4c0-fe79-7c59-825a-cf1e7a39abcb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019de4c0-fe79-7c59-825a-cf1e7a39abcb" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019de4c0-fe79-7c59-825a-cf1e7a39abcb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019de4c0-fe79-702c-b414-e3f1e39fe7d1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019de4c0-fe79-7c59-825a-cf1e7a39abcb" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019de4c0-fe79-702c-b414-e3f1e39fe7d1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_CorporateTermLoanCreditAgreement1.35BMember_019de4c0-fe79-74da-aa61-59ca0f68afcb" xlink:href="fip-20260331.xsd#fip_CorporateTermLoanCreditAgreement1.35BMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c0-fe79-702c-b414-e3f1e39fe7d1" xlink:to="loc_fip_CorporateTermLoanCreditAgreement1.35BMember_019de4c0-fe79-74da-aa61-59ca0f68afcb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_CorporateTermLoanCreditAgreement1.3BMember_019de4c0-fe79-7225-8f17-97321c9a7d42" xlink:href="fip-20260331.xsd#fip_CorporateTermLoanCreditAgreement1.3BMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c0-fe79-702c-b414-e3f1e39fe7d1" xlink:to="loc_fip_CorporateTermLoanCreditAgreement1.3BMember_019de4c0-fe79-7225-8f17-97321c9a7d42" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_CorporateTermLoanCreditAgreement35.4MMember_019de4c0-fe79-7fc7-b28d-d51897741263" xlink:href="fip-20260331.xsd#fip_CorporateTermLoanCreditAgreement35.4MMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c0-fe79-702c-b414-e3f1e39fe7d1" xlink:to="loc_fip_CorporateTermLoanCreditAgreement35.4MMember_019de4c0-fe79-7fc7-b28d-d51897741263" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_CorporateBridgeLoanCreditAgreement1.25BMember_019de4c0-fe79-7a82-a4da-56db130a72f4" xlink:href="fip-20260331.xsd#fip_CorporateBridgeLoanCreditAgreement1.25BMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c0-fe79-702c-b414-e3f1e39fe7d1" xlink:to="loc_fip_CorporateBridgeLoanCreditAgreement1.25BMember_019de4c0-fe79-7a82-a4da-56db130a72f4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_JeffersonCreditAgreementJune2025Member_019de4c0-fe79-73b7-88fe-5c7c591f7907" xlink:href="fip-20260331.xsd#fip_JeffersonCreditAgreementJune2025Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c0-fe79-702c-b414-e3f1e39fe7d1" xlink:to="loc_fip_JeffersonCreditAgreementJune2025Member_019de4c0-fe79-73b7-88fe-5c7c591f7907" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_BackstopJefferson255MMember_019de4c0-fe79-7d93-84b8-9745bc219218" xlink:href="fip-20260331.xsd#fip_BackstopJefferson255MMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4c0-fe79-702c-b414-e3f1e39fe7d1" xlink:to="loc_fip_BackstopJefferson255MMember_019de4c0-fe79-7d93-84b8-9745bc219218" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019de4c0-fe79-7599-aafc-e37d1aab7cd9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019de4c0-e25c-7443-b185-400d51adbacd" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019de4c0-fe79-7599-aafc-e37d1aab7cd9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019de4c0-fe79-7599-aafc-e37d1aab7cd9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019de4c0-fe79-7599-aafc-e37d1aab7cd9" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019de4c0-fe79-7599-aafc-e37d1aab7cd9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019de4c0-fe79-71ea-b13b-b1edbbb75651" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019de4c0-fe79-7599-aafc-e37d1aab7cd9" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019de4c0-fe79-71ea-b13b-b1edbbb75651" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansPayableMember_019de4c0-fe79-749c-a21d-625ff6298b85" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LoansPayableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019de4c0-fe79-71ea-b13b-b1edbbb75651" xlink:to="loc_us-gaap_LoansPayableMember_019de4c0-fe79-749c-a21d-625ff6298b85" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_019de4c0-fe79-7905-89a5-bc57fa1f51a9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019de4c0-fe79-71ea-b13b-b1edbbb75651" xlink:to="loc_us-gaap_LineOfCreditMember_019de4c0-fe79-7905-89a5-bc57fa1f51a9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtWeightedAverageInterestRate_019de4c0-e25c-787e-9c42-764dd87b3efb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShortTermDebtWeightedAverageInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019de4c0-e25c-7d6b-83cb-e52d6a31add9" xlink:to="loc_us-gaap_ShortTermDebtWeightedAverageInterestRate_019de4c0-e25c-787e-9c42-764dd87b3efb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_019de4c0-fe79-702c-b202-0ce45f9b43b5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019de4c0-e25c-7d6b-83cb-e52d6a31add9" xlink:to="loc_us-gaap_LongTermDebt_019de4c0-fe79-702c-b202-0ce45f9b43b5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_019de4c0-fe79-7aa8-bedf-3d531d688fb4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019de4c0-e25c-7d6b-83cb-e52d6a31add9" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_019de4c0-fe79-7aa8-bedf-3d531d688fb4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainsLossesOnRestructuringOfDebt_019de4c0-fe79-7fc1-8d0a-b7ed4bffafc1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainsLossesOnRestructuringOfDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019de4c0-e25c-7d6b-83cb-e52d6a31add9" xlink:to="loc_us-gaap_GainsLossesOnRestructuringOfDebt_019de4c0-fe79-7fc1-8d0a-b7ed4bffafc1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDebtIssuanceCosts_019de4c0-fe79-7ac1-9c8c-dfdc2fb6a1ef" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfDebtIssuanceCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019de4c0-e25c-7d6b-83cb-e52d6a31add9" xlink:to="loc_us-gaap_PaymentsOfDebtIssuanceCosts_019de4c0-fe79-7ac1-9c8c-dfdc2fb6a1ef" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLongTermDebt_019de4c0-fe79-70be-804e-4cb72897ba2c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019de4c0-e25c-7d6b-83cb-e52d6a31add9" xlink:to="loc_us-gaap_OtherLongTermDebt_019de4c0-fe79-70be-804e-4cb72897ba2c" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/FAIRVALUEMEASUREMENTSNarrativeDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#FAIRVALUEMEASUREMENTSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/FAIRVALUEMEASUREMENTSNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019dfa25-7848-7fd9-95c3-404108270a03" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019dfa25-7848-7560-95a8-b961708bd8cd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019dfa25-7848-7fd9-95c3-404108270a03" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019dfa25-7848-7560-95a8-b961708bd8cd" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019dfa25-7848-7309-9c2b-8b6f3fff0908" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019dfa25-7848-7560-95a8-b961708bd8cd" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019dfa25-7848-7309-9c2b-8b6f3fff0908" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019dfa25-7848-7309-9c2b-8b6f3fff0908_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019dfa25-7848-7309-9c2b-8b6f3fff0908" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019dfa25-7848-7309-9c2b-8b6f3fff0908_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019dfa25-7848-76db-a4af-6a760bdd90ee" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019dfa25-7848-7309-9c2b-8b6f3fff0908" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019dfa25-7848-76db-a4af-6a760bdd90ee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_019dfa25-7848-7758-a944-92098ecbe752" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019dfa25-7848-76db-a4af-6a760bdd90ee" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_019dfa25-7848-7758-a944-92098ecbe752" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueAxis_019dfa25-7848-7795-b483-46a173f66bcf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationTechniqueAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019dfa25-7848-7560-95a8-b961708bd8cd" xlink:to="loc_us-gaap_ValuationTechniqueAxis_019dfa25-7848-7795-b483-46a173f66bcf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueDomain_019dfa25-7848-7795-b483-46a173f66bcf_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationTechniqueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ValuationTechniqueAxis_019dfa25-7848-7795-b483-46a173f66bcf" xlink:to="loc_us-gaap_ValuationTechniqueDomain_019dfa25-7848-7795-b483-46a173f66bcf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueDomain_019dfa25-7848-765b-8fce-69816db2136a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationTechniqueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ValuationTechniqueAxis_019dfa25-7848-7795-b483-46a173f66bcf" xlink:to="loc_us-gaap_ValuationTechniqueDomain_019dfa25-7848-765b-8fce-69816db2136a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketApproachValuationTechniqueMember_019dfa25-7848-7f06-888e-91de02d3f269" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MarketApproachValuationTechniqueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationTechniqueDomain_019dfa25-7848-765b-8fce-69816db2136a" xlink:to="loc_us-gaap_MarketApproachValuationTechniqueMember_019dfa25-7848-7f06-888e-91de02d3f269" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeApproachValuationTechniqueMember_019dfa25-7848-7a83-aa51-3fee243e2ec2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeApproachValuationTechniqueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationTechniqueDomain_019dfa25-7848-765b-8fce-69816db2136a" xlink:to="loc_us-gaap_IncomeApproachValuationTechniqueMember_019dfa25-7848-7a83-aa51-3fee243e2ec2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivablesFairValueDisclosure_019dfa25-7848-72c3-9a7b-880a21d21753" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReceivablesFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019dfa25-7848-7fd9-95c3-404108270a03" xlink:to="loc_us-gaap_ReceivablesFairValueDisclosure_019dfa25-7848-72c3-9a7b-880a21d21753" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilities_019dfa25-7848-70e2-b8fa-685f94352802" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019dfa25-7848-7fd9-95c3-404108270a03" xlink:to="loc_us-gaap_DerivativeLiabilities_019dfa25-7848-70e2-b8fa-685f94352802" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAdjustmentOfWarrants_019dfa25-7848-7357-a0c7-76603b22a1d8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAdjustmentOfWarrants"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019dfa25-7848-7fd9-95c3-404108270a03" xlink:to="loc_us-gaap_FairValueAdjustmentOfWarrants_019dfa25-7848-7357-a0c7-76603b22a1d8" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/FAIRVALUEMEASUREMENTSFairValueMeasurementInputsandValuationTechniquesDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#FAIRVALUEMEASUREMENTSFairValueMeasurementInputsandValuationTechniquesDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/FAIRVALUEMEASUREMENTSFairValueMeasurementInputsandValuationTechniquesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_58bedb51-4897-4256-9566-843c4964f0dd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_56e5b684-2768-449f-928b-e3b83c3291f8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_58bedb51-4897-4256-9566-843c4964f0dd" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_56e5b684-2768-449f-928b-e3b83c3291f8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeAxis_c6e43be3-8079-43ac-9167-c5848411b954" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_56e5b684-2768-449f-928b-e3b83c3291f8" xlink:to="loc_us-gaap_MeasurementInputTypeAxis_c6e43be3-8079-43ac-9167-c5848411b954" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_c6e43be3-8079-43ac-9167-c5848411b954_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_c6e43be3-8079-43ac-9167-c5848411b954" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_c6e43be3-8079-43ac-9167-c5848411b954_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_bda6ebe4-eac0-412e-80f0-52ea41b2126f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_c6e43be3-8079-43ac-9167-c5848411b954" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_bda6ebe4-eac0-412e-80f0-52ea41b2126f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputSharePriceMember_dbb9e7e9-989b-43d1-ae08-270ff1a191f1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputSharePriceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_bda6ebe4-eac0-412e-80f0-52ea41b2126f" xlink:to="loc_us-gaap_MeasurementInputSharePriceMember_dbb9e7e9-989b-43d1-ae08-270ff1a191f1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputPriceVolatilityMember_a8b0102f-fac6-46bb-87a3-7517776b7493" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputPriceVolatilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_bda6ebe4-eac0-412e-80f0-52ea41b2126f" xlink:to="loc_us-gaap_MeasurementInputPriceVolatilityMember_a8b0102f-fac6-46bb-87a3-7517776b7493" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputRiskFreeInterestRateMember_ee51ccd4-4adc-47dc-9bee-e66346e80134" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputRiskFreeInterestRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_bda6ebe4-eac0-412e-80f0-52ea41b2126f" xlink:to="loc_us-gaap_MeasurementInputRiskFreeInterestRateMember_ee51ccd4-4adc-47dc-9bee-e66346e80134" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputExpectedDividendRateMember_169597a3-9f14-4b7a-936e-e65132c6891c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputExpectedDividendRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_bda6ebe4-eac0-412e-80f0-52ea41b2126f" xlink:to="loc_us-gaap_MeasurementInputExpectedDividendRateMember_169597a3-9f14-4b7a-936e-e65132c6891c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantsAndRightsOutstanding_bd73c855-f93a-4820-8f61-d2956f253302" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WarrantsAndRightsOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_58bedb51-4897-4256-9566-843c4964f0dd" xlink:to="loc_us-gaap_WarrantsAndRightsOutstanding_bd73c855-f93a-4820-8f61-d2956f253302" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_FairValueAtGrantDateWarrant_fd63d0ff-9e97-412d-b8ee-40caa1253d6e" xlink:href="fip-20260331.xsd#fip_FairValueAtGrantDateWarrant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_58bedb51-4897-4256-9566-843c4964f0dd" xlink:to="loc_fip_FairValueAtGrantDateWarrant_fd63d0ff-9e97-412d-b8ee-40caa1253d6e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantsAndRightsOutstandingMeasurementInput_4a744e8e-3eb3-4dd1-943c-32173ae5e027" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WarrantsAndRightsOutstandingMeasurementInput"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_58bedb51-4897-4256-9566-843c4964f0dd" xlink:to="loc_us-gaap_WarrantsAndRightsOutstandingMeasurementInput_4a744e8e-3eb3-4dd1-943c-32173ae5e027" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantsAndRightsOutstandingTerm_2387c108-41f7-4019-94de-1c8764406a59" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WarrantsAndRightsOutstandingTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_58bedb51-4897-4256-9566-843c4964f0dd" xlink:to="loc_us-gaap_WarrantsAndRightsOutstandingTerm_2387c108-41f7-4019-94de-1c8764406a59" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_WarrantFairValuePerShare_a3dfe373-1a77-4500-acdf-1206b15be077" xlink:href="fip-20260331.xsd#fip_WarrantFairValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_58bedb51-4897-4256-9566-843c4964f0dd" xlink:to="loc_fip_WarrantFairValuePerShare_a3dfe373-1a77-4500-acdf-1206b15be077" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/FAIRVALUEMEASUREMENTSFairValueLiabilitiesMeasuredonRecurringBasisUnobservableInputReconciliationDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#FAIRVALUEMEASUREMENTSFairValueLiabilitiesMeasuredonRecurringBasisUnobservableInputReconciliationDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/FAIRVALUEMEASUREMENTSFairValueLiabilitiesMeasuredonRecurringBasisUnobservableInputReconciliationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_c5bb9d04-d693-4054-8804-2974220ec2c0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_754237ae-43e0-4f86-936e-b05ea3ec7528" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_c5bb9d04-d693-4054-8804-2974220ec2c0" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_754237ae-43e0-4f86-936e-b05ea3ec7528" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_74684ca8-e7c6-45c9-9760-9080a0061ec9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_754237ae-43e0-4f86-936e-b05ea3ec7528" xlink:to="loc_us-gaap_FinancialInstrumentAxis_74684ca8-e7c6-45c9-9760-9080a0061ec9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_74684ca8-e7c6-45c9-9760-9080a0061ec9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_74684ca8-e7c6-45c9-9760-9080a0061ec9" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_74684ca8-e7c6-45c9-9760-9080a0061ec9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_f62b4789-fa09-4892-ad76-038e5ebd0017" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_74684ca8-e7c6-45c9-9760-9080a0061ec9" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_f62b4789-fa09-4892-ad76-038e5ebd0017" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantMember_f2b0f3c1-d7f3-450c-a19a-fb10bcd1db08" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WarrantMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_f62b4789-fa09-4892-ad76-038e5ebd0017" xlink:to="loc_us-gaap_WarrantMember_f2b0f3c1-d7f3-450c-a19a-fb10bcd1db08" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_caae738d-4154-40bc-9302-5f7dbc307d73" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_c5bb9d04-d693-4054-8804-2974220ec2c0" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_caae738d-4154-40bc-9302-5f7dbc307d73" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_6bda1ce3-4b5d-4e14-8666-af8cc7d67fc3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_caae738d-4154-40bc-9302-5f7dbc307d73" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_6bda1ce3-4b5d-4e14-8666-af8cc7d67fc3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPurchasesSalesIssuancesSettlements_42582d78-0e73-45fa-bd94-0e625c7f7a10" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPurchasesSalesIssuancesSettlements"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_caae738d-4154-40bc-9302-5f7dbc307d73" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPurchasesSalesIssuancesSettlements_42582d78-0e73-45fa-bd94-0e625c7f7a10" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisChangeInUnrealizedGainLoss_2aa861ef-4955-4aea-8081-d668e029c12f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisChangeInUnrealizedGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_caae738d-4154-40bc-9302-5f7dbc307d73" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisChangeInUnrealizedGainLoss_2aa861ef-4955-4aea-8081-d668e029c12f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_d107ca5c-005e-4f2b-93b8-e1633ec5ffe8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/FAIRVALUEMEASUREMENTSFairValuebyBalanceSheetGroupingDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#FAIRVALUEMEASUREMENTSFairValuebyBalanceSheetGroupingDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/FAIRVALUEMEASUREMENTSFairValuebyBalanceSheetGroupingDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_74bde02c-0b32-4544-9a73-22e23ad32a30" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_d25d6656-e0dd-4b46-b3d0-9a90140b4a87" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_74bde02c-0b32-4544-9a73-22e23ad32a30" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_d25d6656-e0dd-4b46-b3d0-9a90140b4a87" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_f0210bb2-0f5d-42a3-b7f0-23c060c6c68a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_d25d6656-e0dd-4b46-b3d0-9a90140b4a87" xlink:to="loc_us-gaap_DebtInstrumentAxis_f0210bb2-0f5d-42a3-b7f0-23c060c6c68a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_f0210bb2-0f5d-42a3-b7f0-23c060c6c68a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_f0210bb2-0f5d-42a3-b7f0-23c060c6c68a" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_f0210bb2-0f5d-42a3-b7f0-23c060c6c68a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_cd5e0f6a-1fde-48a2-8b53-3df5142ad9b4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_f0210bb2-0f5d-42a3-b7f0-23c060c6c68a" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_cd5e0f6a-1fde-48a2-8b53-3df5142ad9b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_SeriesA2020BondsMember_21bc2d11-21ce-487a-bac7-efb0a60fc984" xlink:href="fip-20260331.xsd#fip_SeriesA2020BondsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_cd5e0f6a-1fde-48a2-8b53-3df5142ad9b4" xlink:to="loc_fip_SeriesA2020BondsMember_21bc2d11-21ce-487a-bac7-efb0a60fc984" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_SeriesA2021BondsMember_801d73f3-5ce9-4d6d-9409-632b67a24e12" xlink:href="fip-20260331.xsd#fip_SeriesA2021BondsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_cd5e0f6a-1fde-48a2-8b53-3df5142ad9b4" xlink:to="loc_fip_SeriesA2021BondsMember_801d73f3-5ce9-4d6d-9409-632b67a24e12" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_SeriesB2021BondsMember_823e7621-e1fc-4671-ade4-402bfd7ec962" xlink:href="fip-20260331.xsd#fip_SeriesB2021BondsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_cd5e0f6a-1fde-48a2-8b53-3df5142ad9b4" xlink:to="loc_fip_SeriesB2021BondsMember_823e7621-e1fc-4671-ade4-402bfd7ec962" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_SeriesA2024BondsMember_a33bde76-e317-43d2-9631-33948096707b" xlink:href="fip-20260331.xsd#fip_SeriesA2024BondsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_cd5e0f6a-1fde-48a2-8b53-3df5142ad9b4" xlink:to="loc_fip_SeriesA2024BondsMember_a33bde76-e317-43d2-9631-33948096707b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_SeriesB2024BondsMember_945f655c-e5e1-4c4e-87d9-bcb18f63ce94" xlink:href="fip-20260331.xsd#fip_SeriesB2024BondsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_cd5e0f6a-1fde-48a2-8b53-3df5142ad9b4" xlink:to="loc_fip_SeriesB2024BondsMember_945f655c-e5e1-4c4e-87d9-bcb18f63ce94" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_Series2025BondsMember_3e5eadef-2344-46f1-be8d-353c69e9761a" xlink:href="fip-20260331.xsd#fip_Series2025BondsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_cd5e0f6a-1fde-48a2-8b53-3df5142ad9b4" xlink:to="loc_fip_Series2025BondsMember_3e5eadef-2344-46f1-be8d-353c69e9761a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_SeniorNotesDue2032Member_2f0478c4-4105-454c-a5ab-9e38211434d9" xlink:href="fip-20260331.xsd#fip_SeniorNotesDue2032Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_cd5e0f6a-1fde-48a2-8b53-3df5142ad9b4" xlink:to="loc_fip_SeniorNotesDue2032Member_2f0478c4-4105-454c-a5ab-9e38211434d9" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_EB5LoanAgreementMember_8bb3f41c-8048-459f-b84f-f8a5620268c1" xlink:href="fip-20260331.xsd#fip_EB5LoanAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_cd5e0f6a-1fde-48a2-8b53-3df5142ad9b4" xlink:to="loc_fip_EB5LoanAgreementMember_8bb3f41c-8048-459f-b84f-f8a5620268c1" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_EB5.2LoanAgreementMember_745ff140-2234-4cde-be70-96f63322b1e6" xlink:href="fip-20260331.xsd#fip_EB5.2LoanAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_cd5e0f6a-1fde-48a2-8b53-3df5142ad9b4" xlink:to="loc_fip_EB5.2LoanAgreementMember_745ff140-2234-4cde-be70-96f63322b1e6" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_EB5.3LoanAgreementMember_fa105611-00c5-4653-bdbc-9a7cd41b4420" xlink:href="fip-20260331.xsd#fip_EB5.3LoanAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_cd5e0f6a-1fde-48a2-8b53-3df5142ad9b4" xlink:to="loc_fip_EB5.3LoanAgreementMember_fa105611-00c5-4653-bdbc-9a7cd41b4420" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementBasisAxis_eece18a5-3499-4c6a-beb9-da060df27594" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByMeasurementBasisAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_d25d6656-e0dd-4b46-b3d0-9a90140b4a87" xlink:to="loc_us-gaap_FairValueByMeasurementBasisAxis_eece18a5-3499-4c6a-beb9-da060df27594" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_eece18a5-3499-4c6a-beb9-da060df27594_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_eece18a5-3499-4c6a-beb9-da060df27594" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_eece18a5-3499-4c6a-beb9-da060df27594_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueDisclosureItemAmountsDomain_b1731523-9591-4aeb-a54e-65565210be88" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueDisclosureItemAmountsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_eece18a5-3499-4c6a-beb9-da060df27594" xlink:to="loc_us-gaap_FairValueDisclosureItemAmountsDomain_b1731523-9591-4aeb-a54e-65565210be88" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_5a777337-8211-4253-951a-c08e0ca80e4c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_b1731523-9591-4aeb-a54e-65565210be88" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_5a777337-8211-4253-951a-c08e0ca80e4c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_ca4e6c03-ca26-4600-9709-bf7e0fc2ba09" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EstimateOfFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_5a777337-8211-4253-951a-c08e0ca80e4c" xlink:to="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_ca4e6c03-ca26-4600-9709-bf7e0fc2ba09" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesPayableFairValueDisclosure_e70d495a-16b7-46c6-a94e-76e0e06a74ca" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesPayableFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_74bde02c-0b32-4544-9a73-22e23ad32a30" xlink:to="loc_us-gaap_NotesPayableFairValueDisclosure_e70d495a-16b7-46c6-a94e-76e0e06a74ca" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtFairValue_2448042b-d537-4f2b-b87c-f803fe42c56a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_74bde02c-0b32-4544-9a73-22e23ad32a30" xlink:to="loc_us-gaap_LongTermDebtFairValue_2448042b-d537-4f2b-b87c-f803fe42c56a" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/DERIVATIVEFINANCIALINSTRUMENTSNarrativeDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#DERIVATIVEFINANCIALINSTRUMENTSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/DERIVATIVEFINANCIALINSTRUMENTSNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_019dfa0a-c133-7d6f-85b7-da26d9560a29" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_019dfa0a-c133-7a1e-a98c-e1585cc16af0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_019dfa0a-c133-7d6f-85b7-da26d9560a29" xlink:to="loc_us-gaap_DerivativeTable_019dfa0a-c133-7a1e-a98c-e1585cc16af0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_MaturityDateAxis_019dfa0a-c133-7c16-a7d0-6808cf908bb4" xlink:href="fip-20260331.xsd#fip_MaturityDateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_019dfa0a-c133-7a1e-a98c-e1585cc16af0" xlink:to="loc_fip_MaturityDateAxis_019dfa0a-c133-7c16-a7d0-6808cf908bb4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_MaturityDateDomain_019dfa0a-c133-7c16-a7d0-6808cf908bb4_default" xlink:href="fip-20260331.xsd#fip_MaturityDateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_fip_MaturityDateAxis_019dfa0a-c133-7c16-a7d0-6808cf908bb4" xlink:to="loc_fip_MaturityDateDomain_019dfa0a-c133-7c16-a7d0-6808cf908bb4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_MaturityDateDomain_019dfa0a-c133-730b-94f3-c29b8757edcf" xlink:href="fip-20260331.xsd#fip_MaturityDateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_fip_MaturityDateAxis_019dfa0a-c133-7c16-a7d0-6808cf908bb4" xlink:to="loc_fip_MaturityDateDomain_019dfa0a-c133-730b-94f3-c29b8757edcf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_February102026Member_019dfa0a-c133-7547-8448-cb0d647e06fc" xlink:href="fip-20260331.xsd#fip_February102026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_fip_MaturityDateDomain_019dfa0a-c133-730b-94f3-c29b8757edcf" xlink:to="loc_fip_February102026Member_019dfa0a-c133-7547-8448-cb0d647e06fc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_February262026Member_019dfa0a-c133-793b-b0a7-f555c12e722c" xlink:href="fip-20260331.xsd#fip_February262026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_fip_MaturityDateDomain_019dfa0a-c133-730b-94f3-c29b8757edcf" xlink:to="loc_fip_February262026Member_019dfa0a-c133-793b-b0a7-f555c12e722c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_019dfa0a-c133-7ecd-975f-8c64eeea5d77" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LettersOfCreditOutstandingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_019dfa0a-c133-7d6f-85b7-da26d9560a29" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_019dfa0a-c133-7ecd-975f-8c64eeea5d77" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/DERIVATIVEFINANCIALINSTRUMENTSScheduleofDerivativeInstrumentsDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#DERIVATIVEFINANCIALINSTRUMENTSScheduleofDerivativeInstrumentsDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/DERIVATIVEFINANCIALINSTRUMENTSScheduleofDerivativeInstrumentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativesFairValueLineItems_49401f65-5686-4570-ac8d-4e0161899cf8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativesFairValueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_802dee49-f1ea-4eb9-a893-026eb1a69be2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_49401f65-5686-4570-ac8d-4e0161899cf8" xlink:to="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_802dee49-f1ea-4eb9-a893-026eb1a69be2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_d4895a2f-966e-4a63-9218-4c4fae6fc211" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_802dee49-f1ea-4eb9-a893-026eb1a69be2" xlink:to="loc_srt_RangeAxis_d4895a2f-966e-4a63-9218-4c4fae6fc211" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_d4895a2f-966e-4a63-9218-4c4fae6fc211_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_d4895a2f-966e-4a63-9218-4c4fae6fc211" xlink:to="loc_srt_RangeMember_d4895a2f-966e-4a63-9218-4c4fae6fc211_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_b8a944e2-3afd-4765-97c5-6989a07bcda9" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_d4895a2f-966e-4a63-9218-4c4fae6fc211" xlink:to="loc_srt_RangeMember_b8a944e2-3afd-4765-97c5-6989a07bcda9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_b0206637-2df5-41fe-b666-7ba1cdc039b4" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_b8a944e2-3afd-4765-97c5-6989a07bcda9" xlink:to="loc_srt_MinimumMember_b0206637-2df5-41fe-b666-7ba1cdc039b4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_4a8b751b-6062-479e-8a26-dae0bc06d46f" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_b8a944e2-3afd-4765-97c5-6989a07bcda9" xlink:to="loc_srt_MaximumMember_4a8b751b-6062-479e-8a26-dae0bc06d46f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_f1eebd76-c3e7-44f6-8f9a-fb19acea2733" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_802dee49-f1ea-4eb9-a893-026eb1a69be2" xlink:to="loc_us-gaap_HedgingDesignationAxis_f1eebd76-c3e7-44f6-8f9a-fb19acea2733" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_f1eebd76-c3e7-44f6-8f9a-fb19acea2733_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_f1eebd76-c3e7-44f6-8f9a-fb19acea2733" xlink:to="loc_us-gaap_HedgingDesignationDomain_f1eebd76-c3e7-44f6-8f9a-fb19acea2733_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_3c0d8c6c-cc75-4724-8f7e-aedeeb2fcda4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_f1eebd76-c3e7-44f6-8f9a-fb19acea2733" xlink:to="loc_us-gaap_HedgingDesignationDomain_3c0d8c6c-cc75-4724-8f7e-aedeeb2fcda4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_ad3b5953-1ace-453d-a181-50041b89b314" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_3c0d8c6c-cc75-4724-8f7e-aedeeb2fcda4" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_ad3b5953-1ace-453d-a181-50041b89b314" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotDesignatedAsHedgingInstrumentEconomicHedgeMember_5091082e-999d-4c1d-b70f-95d5f290c903" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotDesignatedAsHedgingInstrumentEconomicHedgeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_3c0d8c6c-cc75-4724-8f7e-aedeeb2fcda4" xlink:to="loc_us-gaap_NotDesignatedAsHedgingInstrumentEconomicHedgeMember_5091082e-999d-4c1d-b70f-95d5f290c903" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_47d1f7f6-fb07-4d95-bc1e-b39e616832ec" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_802dee49-f1ea-4eb9-a893-026eb1a69be2" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_47d1f7f6-fb07-4d95-bc1e-b39e616832ec" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_47d1f7f6-fb07-4d95-bc1e-b39e616832ec_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_47d1f7f6-fb07-4d95-bc1e-b39e616832ec" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_47d1f7f6-fb07-4d95-bc1e-b39e616832ec_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_5c28c219-078a-4bea-bb20-36d4cfe1e1eb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_47d1f7f6-fb07-4d95-bc1e-b39e616832ec" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_5c28c219-078a-4bea-bb20-36d4cfe1e1eb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_536cfd3a-b6a7-49e5-80f7-93c665334033" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_5c28c219-078a-4bea-bb20-36d4cfe1e1eb" xlink:to="loc_us-gaap_InterestRateSwapMember_536cfd3a-b6a7-49e5-80f7-93c665334033" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_ElectricitySwapsMember_019dfa0d-e2d7-79d7-a2a6-c6a8d2d5995f" xlink:href="fip-20260331.xsd#fip_ElectricitySwapsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_5c28c219-078a-4bea-bb20-36d4cfe1e1eb" xlink:to="loc_fip_ElectricitySwapsMember_019dfa0d-e2d7-79d7-a2a6-c6a8d2d5995f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NaturalGasReservesMember_2b6c5f39-469e-4041-9a2f-b54934ca9826" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_NaturalGasReservesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_5c28c219-078a-4bea-bb20-36d4cfe1e1eb" xlink:to="loc_srt_NaturalGasReservesMember_2b6c5f39-469e-4041-9a2f-b54934ca9826" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_8133ebfd-c3ba-4e9a-843d-bfc867cacda2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_49401f65-5686-4570-ac8d-4e0161899cf8" xlink:to="loc_us-gaap_DerivativeNotionalAmount_8133ebfd-c3ba-4e9a-843d-bfc867cacda2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueHedgeAssetsAtFairValue_1fe35ed6-1e12-4a2b-82fd-4e3679b42fd0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueHedgeAssetsAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_49401f65-5686-4570-ac8d-4e0161899cf8" xlink:to="loc_us-gaap_FairValueHedgeAssetsAtFairValue_1fe35ed6-1e12-4a2b-82fd-4e3679b42fd0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueHedgeLiabilitiesAtFairValue_bc04fac4-6752-46a7-a9e8-28f84e9911f0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueHedgeLiabilitiesAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_49401f65-5686-4570-ac8d-4e0161899cf8" xlink:to="loc_us-gaap_FairValueHedgeLiabilitiesAtFairValue_bc04fac4-6752-46a7-a9e8-28f84e9911f0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTermOfContract_d1ee7932-7d15-4114-8bc9-bfbb15b0cd4e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeTermOfContract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_49401f65-5686-4570-ac8d-4e0161899cf8" xlink:to="loc_us-gaap_DerivativeTermOfContract_d1ee7932-7d15-4114-8bc9-bfbb15b0cd4e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationGainLossIncludedInEarnings_019dfa0d-e2d7-7a40-bf36-14fd6eaa769b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationGainLossIncludedInEarnings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_49401f65-5686-4570-ac8d-4e0161899cf8" xlink:to="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationGainLossIncludedInEarnings_019dfa0d-e2d7-7a40-bf36-14fd6eaa769b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationSettlements_019dfa15-424a-70b8-9571-73153159b97c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationSettlements"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_49401f65-5686-4570-ac8d-4e0161899cf8" xlink:to="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationSettlements_019dfa15-424a-70b8-9571-73153159b97c" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/DERIVATIVEFINANCIALINSTRUMENTSScheduleofDerivativeLiabilitiesatFairValueDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#DERIVATIVEFINANCIALINSTRUMENTSScheduleofDerivativeLiabilitiesatFairValueDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/DERIVATIVEFINANCIALINSTRUMENTSScheduleofDerivativeLiabilitiesatFairValueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_d94b73ec-646c-4b33-bcca-a2e53e37050e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_889f146e-d3cf-418f-a4b4-295f56beac01" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_d94b73ec-646c-4b33-bcca-a2e53e37050e" xlink:to="loc_us-gaap_DerivativeTable_889f146e-d3cf-418f-a4b4-295f56beac01" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_1e80bf2a-8c40-40c8-9725-0d700e01c9a8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_889f146e-d3cf-418f-a4b4-295f56beac01" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_1e80bf2a-8c40-40c8-9725-0d700e01c9a8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_1e80bf2a-8c40-40c8-9725-0d700e01c9a8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_1e80bf2a-8c40-40c8-9725-0d700e01c9a8" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_1e80bf2a-8c40-40c8-9725-0d700e01c9a8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_ebd35e4c-e39f-4779-b1ec-ff223f81bd0e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_1e80bf2a-8c40-40c8-9725-0d700e01c9a8" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_ebd35e4c-e39f-4779-b1ec-ff223f81bd0e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_ElectricitySwapsMember_9c6c74f8-5280-4448-8ea5-8e6ca22d72de" xlink:href="fip-20260331.xsd#fip_ElectricitySwapsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_ebd35e4c-e39f-4779-b1ec-ff223f81bd0e" xlink:to="loc_fip_ElectricitySwapsMember_9c6c74f8-5280-4448-8ea5-8e6ca22d72de" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_3b051391-38bb-4196-9920-2253a2bb3090" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_ebd35e4c-e39f-4779-b1ec-ff223f81bd0e" xlink:to="loc_us-gaap_InterestRateSwapMember_3b051391-38bb-4196-9920-2253a2bb3090" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NaturalGasReservesMember_019dfa11-d483-7d61-8d14-1ce9afa95e3e" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_NaturalGasReservesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_ebd35e4c-e39f-4779-b1ec-ff223f81bd0e" xlink:to="loc_srt_NaturalGasReservesMember_019dfa11-d483-7d61-8d14-1ce9afa95e3e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationRollForward_851aedb8-b1a2-4d0a-b63f-cdfea4895806" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_d94b73ec-646c-4b33-bcca-a2e53e37050e" xlink:to="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationRollForward_851aedb8-b1a2-4d0a-b63f-cdfea4895806" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisWithUnobservableInputs_b4e93e08-8fda-4cd4-934d-6505a7bf4463" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisWithUnobservableInputs"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationRollForward_851aedb8-b1a2-4d0a-b63f-cdfea4895806" xlink:to="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisWithUnobservableInputs_b4e93e08-8fda-4cd4-934d-6505a7bf4463" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationPurchases_ef1cf883-a675-448c-b281-f553501a0869" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationPurchases"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationRollForward_851aedb8-b1a2-4d0a-b63f-cdfea4895806" xlink:to="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationPurchases_ef1cf883-a675-448c-b281-f553501a0869" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationSettlements_ed812a2f-e7cd-4ba0-ab71-ae4daa03d160" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationSettlements"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationRollForward_851aedb8-b1a2-4d0a-b63f-cdfea4895806" xlink:to="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationSettlements_ed812a2f-e7cd-4ba0-ab71-ae4daa03d160" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationGainLossIncludedInEarnings_c23faf91-1489-44b6-a2cb-6fa889adebb8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationGainLossIncludedInEarnings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationRollForward_851aedb8-b1a2-4d0a-b63f-cdfea4895806" xlink:to="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationGainLossIncludedInEarnings_c23faf91-1489-44b6-a2cb-6fa889adebb8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationGainLossIncludedInOtherComprehensiveIncomeLoss_019dfa15-424a-7891-bf59-968098c43fa3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationGainLossIncludedInOtherComprehensiveIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationRollForward_851aedb8-b1a2-4d0a-b63f-cdfea4895806" xlink:to="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationGainLossIncludedInOtherComprehensiveIncomeLoss_019dfa15-424a-7891-bf59-968098c43fa3" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisChangeInUnrealizedGainLoss_019dfa18-3efa-7fbf-afad-03b0bc89b670" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisChangeInUnrealizedGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationRollForward_851aedb8-b1a2-4d0a-b63f-cdfea4895806" xlink:to="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisChangeInUnrealizedGainLoss_019dfa18-3efa-7fbf-afad-03b0bc89b670" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisWithUnobservableInputs_b293e6e7-51ed-48d8-a28c-ce0d505fcaa0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisWithUnobservableInputs"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/REVENUESComponentsofRevenueDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#REVENUESComponentsofRevenueDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/REVENUESComponentsofRevenueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_7a095bd2-9cbf-4135-b68a-2c500063f875" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_1c3a169d-ebf3-40ca-8254-7cac76685b29" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_7a095bd2-9cbf-4135-b68a-2c500063f875" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_1c3a169d-ebf3-40ca-8254-7cac76685b29" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_b1c3f8a0-3ba8-47d6-924f-f6358584a284" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_1c3a169d-ebf3-40ca-8254-7cac76685b29" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_b1c3f8a0-3ba8-47d6-924f-f6358584a284" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_b1c3f8a0-3ba8-47d6-924f-f6358584a284_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_b1c3f8a0-3ba8-47d6-924f-f6358584a284" xlink:to="loc_us-gaap_SegmentDomain_b1c3f8a0-3ba8-47d6-924f-f6358584a284_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_fe5465e4-b6cc-4b5b-a272-3d55a95cf02e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_b1c3f8a0-3ba8-47d6-924f-f6358584a284" xlink:to="loc_us-gaap_SegmentDomain_fe5465e4-b6cc-4b5b-a272-3d55a95cf02e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_RailroadMember_eee9b69c-e0d5-464a-b079-fbec26b77843" xlink:href="fip-20260331.xsd#fip_RailroadMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_fe5465e4-b6cc-4b5b-a272-3d55a95cf02e" xlink:to="loc_fip_RailroadMember_eee9b69c-e0d5-464a-b079-fbec26b77843" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_JeffersonTerminalMember_a6bfcd0a-0b01-4489-a45c-6889f922810e" xlink:href="fip-20260331.xsd#fip_JeffersonTerminalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_fe5465e4-b6cc-4b5b-a272-3d55a95cf02e" xlink:to="loc_fip_JeffersonTerminalMember_a6bfcd0a-0b01-4489-a45c-6889f922810e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_RapaunoMember_b223dc84-0668-4bdc-a1d2-cc9fef60a705" xlink:href="fip-20260331.xsd#fip_RapaunoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_fe5465e4-b6cc-4b5b-a272-3d55a95cf02e" xlink:to="loc_fip_RapaunoMember_b223dc84-0668-4bdc-a1d2-cc9fef60a705" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_PowerAndGasMember_1be545ad-b7da-4e31-b1dd-772ed538ae0c" xlink:href="fip-20260331.xsd#fip_PowerAndGasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_fe5465e4-b6cc-4b5b-a272-3d55a95cf02e" xlink:to="loc_fip_PowerAndGasMember_1be545ad-b7da-4e31-b1dd-772ed538ae0c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_SustainabilityMember_803ae861-4346-4d48-9ae8-2bbffdab81fe" xlink:href="fip-20260331.xsd#fip_SustainabilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_fe5465e4-b6cc-4b5b-a272-3d55a95cf02e" xlink:to="loc_fip_SustainabilityMember_803ae861-4346-4d48-9ae8-2bbffdab81fe" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_36d99516-347a-4f1d-9677-05c38c46f8f6" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_1c3a169d-ebf3-40ca-8254-7cac76685b29" xlink:to="loc_srt_ProductOrServiceAxis_36d99516-347a-4f1d-9677-05c38c46f8f6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_36d99516-347a-4f1d-9677-05c38c46f8f6_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_36d99516-347a-4f1d-9677-05c38c46f8f6" xlink:to="loc_srt_ProductsAndServicesDomain_36d99516-347a-4f1d-9677-05c38c46f8f6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_79d630d2-50d5-4c48-893f-1f0ecb0db989" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_36d99516-347a-4f1d-9677-05c38c46f8f6" xlink:to="loc_srt_ProductsAndServicesDomain_79d630d2-50d5-4c48-893f-1f0ecb0db989" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LicenseAndServiceMember_a5264427-df19-4e90-ab41-94277504cab4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LicenseAndServiceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_79d630d2-50d5-4c48-893f-1f0ecb0db989" xlink:to="loc_us-gaap_LicenseAndServiceMember_a5264427-df19-4e90-ab41-94277504cab4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_RailRevenueMember_9ee3b85f-8c84-4e83-a972-9fb7717b5e59" xlink:href="fip-20260331.xsd#fip_RailRevenueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_79d630d2-50d5-4c48-893f-1f0ecb0db989" xlink:to="loc_fip_RailRevenueMember_9ee3b85f-8c84-4e83-a972-9fb7717b5e59" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServiceOtherMember_0714cc79-697c-4509-9736-2b9fee53a0c6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ServiceOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_79d630d2-50d5-4c48-893f-1f0ecb0db989" xlink:to="loc_us-gaap_ServiceOtherMember_0714cc79-697c-4509-9736-2b9fee53a0c6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_RoadsideServicesRevenuesMember_6fd8c70e-74ae-4c5e-8f8e-8511ef231c66" xlink:href="fip-20260331.xsd#fip_RoadsideServicesRevenuesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_79d630d2-50d5-4c48-893f-1f0ecb0db989" xlink:to="loc_fip_RoadsideServicesRevenuesMember_6fd8c70e-74ae-4c5e-8f8e-8511ef231c66" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductAndServiceOtherMember_59e1bc49-7554-4211-ba69-8b795e9f0fc5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProductAndServiceOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_79d630d2-50d5-4c48-893f-1f0ecb0db989" xlink:to="loc_us-gaap_ProductAndServiceOtherMember_59e1bc49-7554-4211-ba69-8b795e9f0fc5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_CrudeMarketingRevenuesMember_d437699d-a203-4d32-838b-e8885474ac45" xlink:href="fip-20260331.xsd#fip_CrudeMarketingRevenuesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_79d630d2-50d5-4c48-893f-1f0ecb0db989" xlink:to="loc_fip_CrudeMarketingRevenuesMember_d437699d-a203-4d32-838b-e8885474ac45" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_PowerRevenuesMember_944617b2-3ff4-4fb2-b9d0-06d143dbf47b" xlink:href="fip-20260331.xsd#fip_PowerRevenuesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_79d630d2-50d5-4c48-893f-1f0ecb0db989" xlink:to="loc_fip_PowerRevenuesMember_944617b2-3ff4-4fb2-b9d0-06d143dbf47b" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_GasRevenuesMember_02e02610-9c27-4e59-b1a8-11efcf48ea71" xlink:href="fip-20260331.xsd#fip_GasRevenuesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_79d630d2-50d5-4c48-893f-1f0ecb0db989" xlink:to="loc_fip_GasRevenuesMember_02e02610-9c27-4e59-b1a8-11efcf48ea71" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_6e57a4a1-83fc-40fa-b153-b9e864497fba" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_1c3a169d-ebf3-40ca-8254-7cac76685b29" xlink:to="loc_srt_ConsolidationItemsAxis_6e57a4a1-83fc-40fa-b153-b9e864497fba" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_6e57a4a1-83fc-40fa-b153-b9e864497fba_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_6e57a4a1-83fc-40fa-b153-b9e864497fba" xlink:to="loc_srt_ConsolidationItemsDomain_6e57a4a1-83fc-40fa-b153-b9e864497fba_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_8a4ac0e2-94e2-4a05-956c-2bd9a1cc172c" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_6e57a4a1-83fc-40fa-b153-b9e864497fba" xlink:to="loc_srt_ConsolidationItemsDomain_8a4ac0e2-94e2-4a05-956c-2bd9a1cc172c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_4e0ac1a8-5706-4ec7-8141-fc2dd27a44fc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_8a4ac0e2-94e2-4a05-956c-2bd9a1cc172c" xlink:to="loc_us-gaap_OperatingSegmentsMember_4e0ac1a8-5706-4ec7-8141-fc2dd27a44fc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_f43aff69-f8f4-47e1-90f6-4e90c4a630c1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CorporateNonSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_8a4ac0e2-94e2-4a05-956c-2bd9a1cc172c" xlink:to="loc_us-gaap_CorporateNonSegmentMember_f43aff69-f8f4-47e1-90f6-4e90c4a630c1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_949a5dc0-577c-4d41-97e3-64c21888f146" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_7a095bd2-9cbf-4135-b68a-2c500063f875" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_949a5dc0-577c-4d41-97e3-64c21888f146" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/EQUITYBASEDCOMPENSATIONExpensesRelatedtoStockBasedCompensationExpenseDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#EQUITYBASEDCOMPENSATIONExpensesRelatedtoStockBasedCompensationExpenseDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/EQUITYBASEDCOMPENSATIONExpensesRelatedtoStockBasedCompensationExpenseDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_35771c0c-8ab4-4dfa-9993-cbf5dff83a34" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_016bb50c-db10-4f84-9cc7-4de124f7bf40" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_35771c0c-8ab4-4dfa-9993-cbf5dff83a34" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_016bb50c-db10-4f84-9cc7-4de124f7bf40" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_6bdbb981-e591-43d8-a895-35edeefd3ecb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_016bb50c-db10-4f84-9cc7-4de124f7bf40" xlink:to="loc_us-gaap_AwardTypeAxis_6bdbb981-e591-43d8-a895-35edeefd3ecb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_6bdbb981-e591-43d8-a895-35edeefd3ecb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_6bdbb981-e591-43d8-a895-35edeefd3ecb" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_6bdbb981-e591-43d8-a895-35edeefd3ecb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_d819f7ac-f495-44f5-96a3-99da974aa861" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_6bdbb981-e591-43d8-a895-35edeefd3ecb" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_d819f7ac-f495-44f5-96a3-99da974aa861" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_c604b562-ad52-41db-b753-e967f9df6814" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_d819f7ac-f495-44f5-96a3-99da974aa861" xlink:to="loc_us-gaap_RestrictedStockMember_c604b562-ad52-41db-b753-e967f9df6814" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockCompensationPlanMember_bc7a594e-b259-4078-a751-e7a7f07efa9d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockCompensationPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_d819f7ac-f495-44f5-96a3-99da974aa861" xlink:to="loc_us-gaap_StockCompensationPlanMember_bc7a594e-b259-4078-a751-e7a7f07efa9d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_726e1c4f-5832-4815-9d47-b7b6df953ce1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_d819f7ac-f495-44f5-96a3-99da974aa861" xlink:to="loc_us-gaap_EmployeeStockOptionMember_726e1c4f-5832-4815-9d47-b7b6df953ce1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_fb8c11bb-4776-48c7-95e4-2348340db139" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_016bb50c-db10-4f84-9cc7-4de124f7bf40" xlink:to="loc_srt_ConsolidatedEntitiesAxis_fb8c11bb-4776-48c7-95e4-2348340db139" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_fb8c11bb-4776-48c7-95e4-2348340db139_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_fb8c11bb-4776-48c7-95e4-2348340db139" xlink:to="loc_srt_ConsolidatedEntitiesDomain_fb8c11bb-4776-48c7-95e4-2348340db139_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_9989996c-8fd3-4717-a9fa-76e366cbd50b" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_fb8c11bb-4776-48c7-95e4-2348340db139" xlink:to="loc_srt_ConsolidatedEntitiesDomain_9989996c-8fd3-4717-a9fa-76e366cbd50b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SubsidiariesMember_5b0bd1b1-686f-43ad-aa21-ce81d335cce8" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_SubsidiariesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_9989996c-8fd3-4717-a9fa-76e366cbd50b" xlink:to="loc_srt_SubsidiariesMember_5b0bd1b1-686f-43ad-aa21-ce81d335cce8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ParentCompanyMember_8b3c3224-5a47-41b0-965d-b76efc05f370" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ParentCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_9989996c-8fd3-4717-a9fa-76e366cbd50b" xlink:to="loc_srt_ParentCompanyMember_8b3c3224-5a47-41b0-965d-b76efc05f370" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_667804aa-e959-4255-b445-68b10796277a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_35771c0c-8ab4-4dfa-9993-cbf5dff83a34" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_667804aa-e959-4255-b445-68b10796277a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_eef08d98-0bbb-4590-a4d7-6ac7613e9936" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_35771c0c-8ab4-4dfa-9993-cbf5dff83a34" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_eef08d98-0bbb-4590-a4d7-6ac7613e9936" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms_bb4ce11f-73a6-41c2-888a-47a0fce0d6b3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_35771c0c-8ab4-4dfa-9993-cbf5dff83a34" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms_bb4ce11f-73a6-41c2-888a-47a0fce0d6b3" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/EQUITYBASEDCOMPENSATIONNarrativeDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#EQUITYBASEDCOMPENSATIONNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/EQUITYBASEDCOMPENSATIONNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dfa20-c70a-7f88-b33f-80b2332db563" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019dfa20-c70a-7e63-bbf1-6853ca2219e8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dfa20-c70a-7f88-b33f-80b2332db563" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019dfa20-c70a-7e63-bbf1-6853ca2219e8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_019dfa20-c70a-75fe-99ce-2b4f5e790211" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019dfa20-c70a-7e63-bbf1-6853ca2219e8" xlink:to="loc_us-gaap_PlanNameAxis_019dfa20-c70a-75fe-99ce-2b4f5e790211" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019dfa20-c70a-75fe-99ce-2b4f5e790211_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_019dfa20-c70a-75fe-99ce-2b4f5e790211" xlink:to="loc_us-gaap_PlanNameDomain_019dfa20-c70a-75fe-99ce-2b4f5e790211_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019dfa20-c70a-76bc-851e-d70cd34e4a8e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_019dfa20-c70a-75fe-99ce-2b4f5e790211" xlink:to="loc_us-gaap_PlanNameDomain_019dfa20-c70a-76bc-851e-d70cd34e4a8e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_NonqualifiedStockOptionAndIncentiveAwardPlanMember_019dfa20-c70a-7e8e-a651-100f5980153b" xlink:href="fip-20260331.xsd#fip_NonqualifiedStockOptionAndIncentiveAwardPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_019dfa20-c70a-76bc-851e-d70cd34e4a8e" xlink:to="loc_fip_NonqualifiedStockOptionAndIncentiveAwardPlanMember_019dfa20-c70a-7e8e-a651-100f5980153b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019dfa20-c70a-7223-9a2f-b5c9df259b5e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019dfa20-c70a-7e63-bbf1-6853ca2219e8" xlink:to="loc_us-gaap_AwardTypeAxis_019dfa20-c70a-7223-9a2f-b5c9df259b5e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019dfa20-c70a-7223-9a2f-b5c9df259b5e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019dfa20-c70a-7223-9a2f-b5c9df259b5e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019dfa20-c70a-7223-9a2f-b5c9df259b5e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019dfa20-c70a-7612-be37-36beae457cf2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019dfa20-c70a-7223-9a2f-b5c9df259b5e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019dfa20-c70a-7612-be37-36beae457cf2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_019dfa20-c70a-7521-a14b-c988bccc87e6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019dfa20-c70a-7612-be37-36beae457cf2" xlink:to="loc_us-gaap_EmployeeStockOptionMember_019dfa20-c70a-7521-a14b-c988bccc87e6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_019dfa20-c70a-7426-8825-e7414abd40fc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019dfa20-c70a-7612-be37-36beae457cf2" xlink:to="loc_us-gaap_RestrictedStockMember_019dfa20-c70a-7426-8825-e7414abd40fc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_019dfa20-c70a-7048-b6b2-7c459f2c8aa6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dfa20-c70a-7f88-b33f-80b2332db563" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_019dfa20-c70a-7048-b6b2-7c459f2c8aa6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod_019dfa20-c70a-783a-a812-e0b555340caf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dfa20-c70a-7f88-b33f-80b2332db563" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod_019dfa20-c70a-783a-a812-e0b555340caf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_019dfa20-c70a-74c7-8f22-9710e6302e09" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dfa20-c70a-7f88-b33f-80b2332db563" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_019dfa20-c70a-74c7-8f22-9710e6302e09" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_019dfa20-c70a-7954-9cfb-5a02a9b0fd70" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dfa20-c70a-7f88-b33f-80b2332db563" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_019dfa20-c70a-7954-9cfb-5a02a9b0fd70" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantedFairValue_019dfa20-c70a-78c0-b86e-b4cfbc2c43b7" xlink:href="fip-20260331.xsd#fip_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantedFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dfa20-c70a-7f88-b33f-80b2332db563" xlink:to="loc_fip_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantedFairValue_019dfa20-c70a-78c0-b86e-b4cfbc2c43b7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsGrantedinPeriodGrantDateFairValue_019dfa20-c70a-7229-9fc7-412b5152ea6e" xlink:href="fip-20260331.xsd#fip_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsGrantedinPeriodGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dfa20-c70a-7f88-b33f-80b2332db563" xlink:to="loc_fip_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsGrantedinPeriodGrantDateFairValue_019dfa20-c70a-7229-9fc7-412b5152ea6e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedGrantDateFairValue_019dfa20-e16b-7997-9f7d-961d093e8bec" xlink:href="fip-20260331.xsd#fip_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019dfa20-c70a-7f88-b33f-80b2332db563" xlink:to="loc_fip_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedGrantDateFairValue_019dfa20-e16b-7997-9f7d-961d093e8bec" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/MANAGEMENTAGREEMENTANDAFFILIATETRANSACTIONSNarrativeDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#MANAGEMENTAGREEMENTANDAFFILIATETRANSACTIONSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/MANAGEMENTAGREEMENTANDAFFILIATETRANSACTIONSNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_019dfa2e-c46e-72fb-aaa5-9cb93da9882a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019dfa2e-c46e-710b-b289-483f9b733610" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dfa2e-c46e-72fb-aaa5-9cb93da9882a" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019dfa2e-c46e-710b-b289-483f9b733610" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019dfa2e-c46e-73f7-bc64-43831b3ce2fe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019dfa2e-c46e-710b-b289-483f9b733610" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019dfa2e-c46e-73f7-bc64-43831b3ce2fe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019dfa2e-c46e-73f7-bc64-43831b3ce2fe_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019dfa2e-c46e-73f7-bc64-43831b3ce2fe" xlink:to="loc_us-gaap_RelatedPartyDomain_019dfa2e-c46e-73f7-bc64-43831b3ce2fe_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019dfa2e-c46e-75a7-b781-89959fa594d9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019dfa2e-c46e-73f7-bc64-43831b3ce2fe" xlink:to="loc_us-gaap_RelatedPartyDomain_019dfa2e-c46e-75a7-b781-89959fa594d9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AffiliatedEntityMember_019dfa2e-c46e-7567-b8fd-e19265a0d17e" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_AffiliatedEntityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019dfa2e-c46e-75a7-b781-89959fa594d9" xlink:to="loc_srt_AffiliatedEntityMember_019dfa2e-c46e-7567-b8fd-e19265a0d17e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_FortressWorldwideTransportationandInfrastructureMasterGPLLPMember_019dfa2e-c46e-7d3a-89ba-9a1e68450b5d" xlink:href="fip-20260331.xsd#fip_FortressWorldwideTransportationandInfrastructureMasterGPLLPMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019dfa2e-c46e-75a7-b781-89959fa594d9" xlink:to="loc_fip_FortressWorldwideTransportationandInfrastructureMasterGPLLPMember_019dfa2e-c46e-7d3a-89ba-9a1e68450b5d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_IncomeIncentiveAllocationThresholdAxis_019dfa2e-c46e-72e2-aa35-9974ea0ecd81" xlink:href="fip-20260331.xsd#fip_IncomeIncentiveAllocationThresholdAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019dfa2e-c46e-710b-b289-483f9b733610" xlink:to="loc_fip_IncomeIncentiveAllocationThresholdAxis_019dfa2e-c46e-72e2-aa35-9974ea0ecd81" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_IncomeIncentiveAllocationThresholdDomain_019dfa2e-c46e-72e2-aa35-9974ea0ecd81_default" xlink:href="fip-20260331.xsd#fip_IncomeIncentiveAllocationThresholdDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_fip_IncomeIncentiveAllocationThresholdAxis_019dfa2e-c46e-72e2-aa35-9974ea0ecd81" xlink:to="loc_fip_IncomeIncentiveAllocationThresholdDomain_019dfa2e-c46e-72e2-aa35-9974ea0ecd81_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_IncomeIncentiveAllocationThresholdDomain_019dfa2e-c46e-7e55-810d-c7d897e3a6cc" xlink:href="fip-20260331.xsd#fip_IncomeIncentiveAllocationThresholdDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_fip_IncomeIncentiveAllocationThresholdAxis_019dfa2e-c46e-72e2-aa35-9974ea0ecd81" xlink:to="loc_fip_IncomeIncentiveAllocationThresholdDomain_019dfa2e-c46e-7e55-810d-c7d897e3a6cc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_Threshold1Member_019dfa2e-c46e-7e46-baa0-719cc6496470" xlink:href="fip-20260331.xsd#fip_Threshold1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_fip_IncomeIncentiveAllocationThresholdDomain_019dfa2e-c46e-7e55-810d-c7d897e3a6cc" xlink:to="loc_fip_Threshold1Member_019dfa2e-c46e-7e46-baa0-719cc6496470" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_Threshold2Member_019dfa2e-c46e-740a-9bcc-cff1dc259f10" xlink:href="fip-20260331.xsd#fip_Threshold2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_fip_IncomeIncentiveAllocationThresholdDomain_019dfa2e-c46e-7e55-810d-c7d897e3a6cc" xlink:to="loc_fip_Threshold2Member_019dfa2e-c46e-740a-9bcc-cff1dc259f10" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_Threshold3Member_019dfa2e-c46e-73b5-9073-607709224aaf" xlink:href="fip-20260331.xsd#fip_Threshold3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_fip_IncomeIncentiveAllocationThresholdDomain_019dfa2e-c46e-7e55-810d-c7d897e3a6cc" xlink:to="loc_fip_Threshold3Member_019dfa2e-c46e-73b5-9073-607709224aaf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionAxis_019dfa2e-c46e-7465-a361-137a81d91628" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019dfa2e-c46e-710b-b289-483f9b733610" xlink:to="loc_us-gaap_RelatedPartyTransactionAxis_019dfa2e-c46e-7465-a361-137a81d91628" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionDomain_019dfa2e-c46e-7465-a361-137a81d91628_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionAxis_019dfa2e-c46e-7465-a361-137a81d91628" xlink:to="loc_us-gaap_RelatedPartyTransactionDomain_019dfa2e-c46e-7465-a361-137a81d91628_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionDomain_019dfa2e-c46e-7f02-975d-46a4912ba901" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionAxis_019dfa2e-c46e-7465-a361-137a81d91628" xlink:to="loc_us-gaap_RelatedPartyTransactionDomain_019dfa2e-c46e-7f02-975d-46a4912ba901" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_IncomeIncentiveAllocationMember_019dfa2e-c46e-704b-8823-8807abc7edba" xlink:href="fip-20260331.xsd#fip_IncomeIncentiveAllocationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionDomain_019dfa2e-c46e-7f02-975d-46a4912ba901" xlink:to="loc_fip_IncomeIncentiveAllocationMember_019dfa2e-c46e-704b-8823-8807abc7edba" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_ManagementFeesMember_019dfa31-9ed3-708d-9f5c-0e243bbfe246" xlink:href="fip-20260331.xsd#fip_ManagementFeesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionDomain_019dfa2e-c46e-7f02-975d-46a4912ba901" xlink:to="loc_fip_ManagementFeesMember_019dfa31-9ed3-708d-9f5c-0e243bbfe246" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019dfa2e-c46e-7dc0-9ae5-9927c376ae7b" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019dfa2e-c46e-710b-b289-483f9b733610" xlink:to="loc_srt_RangeAxis_019dfa2e-c46e-7dc0-9ae5-9927c376ae7b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019dfa2e-c46e-7dc0-9ae5-9927c376ae7b_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019dfa2e-c46e-7dc0-9ae5-9927c376ae7b" xlink:to="loc_srt_RangeMember_019dfa2e-c46e-7dc0-9ae5-9927c376ae7b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019dfa2e-c46e-7f13-a050-c0036cda4feb" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019dfa2e-c46e-7dc0-9ae5-9927c376ae7b" xlink:to="loc_srt_RangeMember_019dfa2e-c46e-7f13-a050-c0036cda4feb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019dfa2e-c46e-75b7-baff-049fdd8c0d61" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019dfa2e-c46e-7f13-a050-c0036cda4feb" xlink:to="loc_srt_MinimumMember_019dfa2e-c46e-75b7-baff-049fdd8c0d61" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019dfa2e-c46e-72d8-8604-b123ba0dc307" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019dfa2e-c46e-7f13-a050-c0036cda4feb" xlink:to="loc_srt_MaximumMember_019dfa2e-c46e-72d8-8604-b123ba0dc307" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019dfa2e-fd95-7ed9-8a19-9ce674bf13a8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019dfa2e-c46e-710b-b289-483f9b733610" xlink:to="loc_us-gaap_AwardTypeAxis_019dfa2e-fd95-7ed9-8a19-9ce674bf13a8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019dfa2e-fd95-7ed9-8a19-9ce674bf13a8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019dfa2e-fd95-7ed9-8a19-9ce674bf13a8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019dfa2e-fd95-7ed9-8a19-9ce674bf13a8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019dfa2e-fd95-7d25-a31b-90546a2d42f9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019dfa2e-fd95-7ed9-8a19-9ce674bf13a8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019dfa2e-fd95-7d25-a31b-90546a2d42f9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_019dfa2e-fd95-70d4-9017-3ca921ff622d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019dfa2e-fd95-7d25-a31b-90546a2d42f9" xlink:to="loc_us-gaap_EmployeeStockOptionMember_019dfa2e-fd95-70d4-9017-3ca921ff622d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_OptionsExercisedByManagerMember_019dfa2e-fd95-75bf-8b7a-2e2a7b538c71" xlink:href="fip-20260331.xsd#fip_OptionsExercisedByManagerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019dfa2e-fd95-7d25-a31b-90546a2d42f9" xlink:to="loc_fip_OptionsExercisedByManagerMember_019dfa2e-fd95-75bf-8b7a-2e2a7b538c71" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipAxis_019dfa2f-1413-784e-add0-d5e9eaca1610" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_OwnershipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019dfa2e-c46e-710b-b289-483f9b733610" xlink:to="loc_srt_OwnershipAxis_019dfa2f-1413-784e-add0-d5e9eaca1610" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_019dfa2f-1413-784e-add0-d5e9eaca1610_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_OwnershipAxis_019dfa2f-1413-784e-add0-d5e9eaca1610" xlink:to="loc_srt_OwnershipDomain_019dfa2f-1413-784e-add0-d5e9eaca1610_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_019dfa2f-1413-7169-88b8-fc9ae33d6c88" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_OwnershipAxis_019dfa2f-1413-784e-add0-d5e9eaca1610" xlink:to="loc_srt_OwnershipDomain_019dfa2f-1413-7169-88b8-fc9ae33d6c88" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_JeffersonTerminalMember_019dfa2f-1413-75b7-b74a-3a245accf996" xlink:href="fip-20260331.xsd#fip_JeffersonTerminalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_019dfa2f-1413-7169-88b8-fc9ae33d6c88" xlink:to="loc_fip_JeffersonTerminalMember_019dfa2f-1413-75b7-b74a-3a245accf996" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_RelatedPartyAgreementTerm_019dfa2e-c46e-7480-ad80-147ba7841057" xlink:href="fip-20260331.xsd#fip_RelatedPartyAgreementTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dfa2e-c46e-72fb-aaa5-9cb93da9882a" xlink:to="loc_fip_RelatedPartyAgreementTerm_019dfa2e-c46e-7480-ad80-147ba7841057" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_RelatedPartyTransactionManagementFeePercentFee_019dfa2e-c46e-7f0a-be8b-32a5d5cae315" xlink:href="fip-20260331.xsd#fip_RelatedPartyTransactionManagementFeePercentFee"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dfa2e-c46e-72fb-aaa5-9cb93da9882a" xlink:to="loc_fip_RelatedPartyTransactionManagementFeePercentFee_019dfa2e-c46e-7f0a-be8b-32a5d5cae315" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_RelatedPartyTransactionIncomeIncentiveAllocationPercentofPreincentiveAllocationNetIncome_019dfa2e-c46e-726f-9bbb-ae0379977401" xlink:href="fip-20260331.xsd#fip_RelatedPartyTransactionIncomeIncentiveAllocationPercentofPreincentiveAllocationNetIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dfa2e-c46e-72fb-aaa5-9cb93da9882a" xlink:to="loc_fip_RelatedPartyTransactionIncomeIncentiveAllocationPercentofPreincentiveAllocationNetIncome_019dfa2e-c46e-726f-9bbb-ae0379977401" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_RelatedPartyTransactionIncomeIncentiveAllocationQuarterlyPercentThresholdOfPreIncentiveAllocationNetIncome_019dfa2e-c46e-78dd-8101-b4b0fa19866b" xlink:href="fip-20260331.xsd#fip_RelatedPartyTransactionIncomeIncentiveAllocationQuarterlyPercentThresholdOfPreIncentiveAllocationNetIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dfa2e-c46e-72fb-aaa5-9cb93da9882a" xlink:to="loc_fip_RelatedPartyTransactionIncomeIncentiveAllocationQuarterlyPercentThresholdOfPreIncentiveAllocationNetIncome_019dfa2e-c46e-78dd-8101-b4b0fa19866b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_RelatedPartyTransactionIncomeIncentiveAllocationAnnualPercentThresholdOfPreIncentiveAllocationNetIncome_019dfa2e-c46e-7b9e-8557-4489a22a68f7" xlink:href="fip-20260331.xsd#fip_RelatedPartyTransactionIncomeIncentiveAllocationAnnualPercentThresholdOfPreIncentiveAllocationNetIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dfa2e-c46e-72fb-aaa5-9cb93da9882a" xlink:to="loc_fip_RelatedPartyTransactionIncomeIncentiveAllocationAnnualPercentThresholdOfPreIncentiveAllocationNetIncome_019dfa2e-c46e-7b9e-8557-4489a22a68f7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_CapitalGainsAllocationProRataSharePercentage_019dfa2e-df48-7d41-810b-d17cd85d80ea" xlink:href="fip-20260331.xsd#fip_CapitalGainsAllocationProRataSharePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dfa2e-c46e-72fb-aaa5-9cb93da9882a" xlink:to="loc_fip_CapitalGainsAllocationProRataSharePercentage_019dfa2e-df48-7d41-810b-d17cd85d80ea" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_SaleOfStockPurchaseOptionPercentageOfCommonSharesSold_019dfa2e-fd95-7e8c-9d78-b165763de45e" xlink:href="fip-20260331.xsd#fip_SaleOfStockPurchaseOptionPercentageOfCommonSharesSold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dfa2e-c46e-72fb-aaa5-9cb93da9882a" xlink:to="loc_fip_SaleOfStockPurchaseOptionPercentageOfCommonSharesSold_019dfa2e-fd95-7e8c-9d78-b165763de45e" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_SaleOfStockPurchaseOptionPercentageOfGrossCapitalInEquityIssuance_019dfa2e-fd95-78da-89cc-51fcfee52f67" xlink:href="fip-20260331.xsd#fip_SaleOfStockPurchaseOptionPercentageOfGrossCapitalInEquityIssuance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dfa2e-c46e-72fb-aaa5-9cb93da9882a" xlink:to="loc_fip_SaleOfStockPurchaseOptionPercentageOfGrossCapitalInEquityIssuance_019dfa2e-fd95-78da-89cc-51fcfee52f67" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_019dfa2e-fd95-7fe6-9cee-4f9e968ae77b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dfa2e-c46e-72fb-aaa5-9cb93da9882a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_019dfa2e-fd95-7fe6-9cee-4f9e968ae77b" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_019dfa2e-fd95-77f3-8248-6c8238cf0853" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dfa2e-c46e-72fb-aaa5-9cb93da9882a" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_019dfa2e-fd95-77f3-8248-6c8238cf0853" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_019dfa2e-fd95-7bd9-816f-73fe758d6609" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dfa2e-c46e-72fb-aaa5-9cb93da9882a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_019dfa2e-fd95-7bd9-816f-73fe758d6609" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod_019dfa2e-fd95-7a7d-b955-838d56f894b4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dfa2e-c46e-72fb-aaa5-9cb93da9882a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod_019dfa2e-fd95-7a7d-b955-838d56f894b4" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners_019dfa2f-1413-7fd0-aef4-8238300b6a6e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dfa2e-c46e-72fb-aaa5-9cb93da9882a" xlink:to="loc_us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners_019dfa2f-1413-7fd0-aef4-8238300b6a6e" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterest_019dfa2f-1413-7707-8c21-3ffe4f215e02" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MinorityInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dfa2e-c46e-72fb-aaa5-9cb93da9882a" xlink:to="loc_us-gaap_MinorityInterest_019dfa2f-1413-7707-8c21-3ffe4f215e02" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromPaymentsToMinorityShareholders_019dfa2f-1413-7a23-9752-48e4e78c8d7a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromPaymentsToMinorityShareholders"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dfa2e-c46e-72fb-aaa5-9cb93da9882a" xlink:to="loc_us-gaap_ProceedsFromPaymentsToMinorityShareholders_019dfa2f-1413-7a23-9752-48e4e78c8d7a" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseExpense_019dfa2f-2802-79f9-87af-4ce945140f85" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dfa2e-c46e-72fb-aaa5-9cb93da9882a" xlink:to="loc_us-gaap_OperatingLeaseExpense_019dfa2f-2802-79f9-87af-4ce945140f85" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesReceivableNet_019dfa31-9ed3-7f13-9757-9cd334f97ee1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesReceivableNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019dfa2e-c46e-72fb-aaa5-9cb93da9882a" xlink:to="loc_us-gaap_NotesReceivableNet_019dfa31-9ed3-7f13-9757-9cd334f97ee1" xlink:type="arc" order="16"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/MANAGEMENTAGREEMENTANDAFFILIATETRANSACTIONSScheduleofRelatedPartyTransactionsDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#MANAGEMENTAGREEMENTANDAFFILIATETRANSACTIONSScheduleofRelatedPartyTransactionsDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/MANAGEMENTAGREEMENTANDAFFILIATETRANSACTIONSScheduleofRelatedPartyTransactionsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_52fb242a-30f2-45f5-81f9-6bee26a13588" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_b219b916-204a-4cc5-ad49-60a3dfad8879" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_52fb242a-30f2-45f5-81f9-6bee26a13588" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_b219b916-204a-4cc5-ad49-60a3dfad8879" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionAxis_51a61a16-70c7-47a6-a704-8d915cf3c3c9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_b219b916-204a-4cc5-ad49-60a3dfad8879" xlink:to="loc_us-gaap_RelatedPartyTransactionAxis_51a61a16-70c7-47a6-a704-8d915cf3c3c9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionDomain_51a61a16-70c7-47a6-a704-8d915cf3c3c9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionAxis_51a61a16-70c7-47a6-a704-8d915cf3c3c9" xlink:to="loc_us-gaap_RelatedPartyTransactionDomain_51a61a16-70c7-47a6-a704-8d915cf3c3c9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionDomain_7d8a261f-b027-4302-b0df-9a014c32dda3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionAxis_51a61a16-70c7-47a6-a704-8d915cf3c3c9" xlink:to="loc_us-gaap_RelatedPartyTransactionDomain_7d8a261f-b027-4302-b0df-9a014c32dda3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_PostIPOManagementFeesMember_c8eef633-f1be-4618-981d-f21c9469feb8" xlink:href="fip-20260331.xsd#fip_PostIPOManagementFeesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionDomain_7d8a261f-b027-4302-b0df-9a014c32dda3" xlink:to="loc_fip_PostIPOManagementFeesMember_c8eef633-f1be-4618-981d-f21c9469feb8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_IncomeIncentiveAllocationMember_8c48ed3b-6626-44da-acf7-860553fcddcb" xlink:href="fip-20260331.xsd#fip_IncomeIncentiveAllocationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionDomain_7d8a261f-b027-4302-b0df-9a014c32dda3" xlink:to="loc_fip_IncomeIncentiveAllocationMember_8c48ed3b-6626-44da-acf7-860553fcddcb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_CapitalGainsIncentiveAllocationMember_29b0dac5-fae9-4d99-b43b-491c43c5c898" xlink:href="fip-20260331.xsd#fip_CapitalGainsIncentiveAllocationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionDomain_7d8a261f-b027-4302-b0df-9a014c32dda3" xlink:to="loc_fip_CapitalGainsIncentiveAllocationMember_29b0dac5-fae9-4d99-b43b-491c43c5c898" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpenseMember_7e8c6e61-2438-4ea4-a549-a2293398bd0e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeneralAndAdministrativeExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionDomain_7d8a261f-b027-4302-b0df-9a014c32dda3" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpenseMember_7e8c6e61-2438-4ea4-a549-a2293398bd0e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_AcquisitionandTransactionExpensesMember_10a0e278-46c2-4198-a7ab-ba900f71d9c8" xlink:href="fip-20260331.xsd#fip_AcquisitionandTransactionExpensesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionDomain_7d8a261f-b027-4302-b0df-9a014c32dda3" xlink:to="loc_fip_AcquisitionandTransactionExpensesMember_10a0e278-46c2-4198-a7ab-ba900f71d9c8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_ef04028e-cf70-477d-8b15-015b92274f74" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_b219b916-204a-4cc5-ad49-60a3dfad8879" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_ef04028e-cf70-477d-8b15-015b92274f74" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_ef04028e-cf70-477d-8b15-015b92274f74_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_ef04028e-cf70-477d-8b15-015b92274f74" xlink:to="loc_us-gaap_RelatedPartyDomain_ef04028e-cf70-477d-8b15-015b92274f74_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_49934035-bc4c-4c0a-a7d1-67cc6d433c67" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_ef04028e-cf70-477d-8b15-015b92274f74" xlink:to="loc_us-gaap_RelatedPartyDomain_49934035-bc4c-4c0a-a7d1-67cc6d433c67" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralPartnerMember_5329269b-3bc4-4220-8ddb-8fc38383b5f4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeneralPartnerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_49934035-bc4c-4c0a-a7d1-67cc6d433c67" xlink:to="loc_us-gaap_GeneralPartnerMember_5329269b-3bc4-4220-8ddb-8fc38383b5f4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AffiliatedEntityMember_ec2aa304-f6c3-4edb-a9df-dff3ea2a865d" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_AffiliatedEntityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_49934035-bc4c-4c0a-a7d1-67cc6d433c67" xlink:to="loc_srt_AffiliatedEntityMember_ec2aa304-f6c3-4edb-a9df-dff3ea2a865d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_18282a58-865f-4942-b67d-311e985b8ad5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BalanceSheetLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_b219b916-204a-4cc5-ad49-60a3dfad8879" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_18282a58-865f-4942-b67d-311e985b8ad5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_18282a58-865f-4942-b67d-311e985b8ad5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_18282a58-865f-4942-b67d-311e985b8ad5" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_18282a58-865f-4942-b67d-311e985b8ad5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_50bd9866-b69c-4938-b874-67e7e927dbbd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_18282a58-865f-4942-b67d-311e985b8ad5" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_50bd9866-b69c-4938-b874-67e7e927dbbd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesMember_f86d6b41-a9c6-4802-9535-b675b628f21a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_50bd9866-b69c-4938-b874-67e7e927dbbd" xlink:to="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesMember_f86d6b41-a9c6-4802-9535-b675b628f21a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipAxis_253cf7f6-9fcf-4be4-a954-1741e448688b" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_OwnershipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_b219b916-204a-4cc5-ad49-60a3dfad8879" xlink:to="loc_srt_OwnershipAxis_253cf7f6-9fcf-4be4-a954-1741e448688b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_253cf7f6-9fcf-4be4-a954-1741e448688b_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_OwnershipAxis_253cf7f6-9fcf-4be4-a954-1741e448688b" xlink:to="loc_srt_OwnershipDomain_253cf7f6-9fcf-4be4-a954-1741e448688b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_f6a28f53-fb68-45f9-a13d-bc3b4c22dba9" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_OwnershipAxis_253cf7f6-9fcf-4be4-a954-1741e448688b" xlink:to="loc_srt_OwnershipDomain_f6a28f53-fb68-45f9-a13d-bc3b4c22dba9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_JeffersonTerminalMember_b5f147dc-71bf-4b3a-85b3-3eceedfaabf7" xlink:href="fip-20260331.xsd#fip_JeffersonTerminalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_f6a28f53-fb68-45f9-a13d-bc3b4c22dba9" xlink:to="loc_fip_JeffersonTerminalMember_b5f147dc-71bf-4b3a-85b3-3eceedfaabf7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_RelatedPartyTransactionIncomeExpensesFromTransactionsWithRelatedParty_92f2cf83-9a07-416a-9163-ebeae7fc74dd" xlink:href="fip-20260331.xsd#fip_RelatedPartyTransactionIncomeExpensesFromTransactionsWithRelatedParty"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_52fb242a-30f2-45f5-81f9-6bee26a13588" xlink:to="loc_fip_RelatedPartyTransactionIncomeExpensesFromTransactionsWithRelatedParty_92f2cf83-9a07-416a-9163-ebeae7fc74dd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAndExpensesRelatedParty_8f67a37a-0951-4ea9-ba18-6a0007aaa0d0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostsAndExpensesRelatedParty"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_52fb242a-30f2-45f5-81f9-6bee26a13588" xlink:to="loc_us-gaap_CostsAndExpensesRelatedParty_8f67a37a-0951-4ea9-ba18-6a0007aaa0d0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ManagementFeePayable_4a8c8b5b-2ec9-4275-8637-c4444ab80e05" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ManagementFeePayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_52fb242a-30f2-45f5-81f9-6bee26a13588" xlink:to="loc_us-gaap_ManagementFeePayable_4a8c8b5b-2ec9-4275-8637-c4444ab80e05" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableOtherCurrentAndNoncurrent_53b81094-cf03-451b-ae9e-c90eed486dba" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableOtherCurrentAndNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_52fb242a-30f2-45f5-81f9-6bee26a13588" xlink:to="loc_us-gaap_AccountsPayableOtherCurrentAndNoncurrent_53b81094-cf03-451b-ae9e-c90eed486dba" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_13f6e249-001a-48b1-9c93-88c94573bcc8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_52fb242a-30f2-45f5-81f9-6bee26a13588" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_13f6e249-001a-48b1-9c93-88c94573bcc8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_ce22aad2-f21c-4ad1-ae17-c18c8ba8a372" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_52fb242a-30f2-45f5-81f9-6bee26a13588" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_ce22aad2-f21c-4ad1-ae17-c18c8ba8a372" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_7fac7a79-2036-42fb-b01b-780ead00459b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_52fb242a-30f2-45f5-81f9-6bee26a13588" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_7fac7a79-2036-42fb-b01b-780ead00459b" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/SEGMENTINFORMATIONStatementofIncomebySegmentDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#SEGMENTINFORMATIONStatementofIncomebySegmentDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/SEGMENTINFORMATIONStatementofIncomebySegmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_205dbca7-fb1c-433c-9da0-ac35f444bbaa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_201a32c7-1dcd-45b2-851d-5b1084e79651" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_205dbca7-fb1c-433c-9da0-ac35f444bbaa" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_201a32c7-1dcd-45b2-851d-5b1084e79651" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_d4454aa7-13f6-4a17-8350-4b7ac467c934" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_201a32c7-1dcd-45b2-851d-5b1084e79651" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_d4454aa7-13f6-4a17-8350-4b7ac467c934" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_d4454aa7-13f6-4a17-8350-4b7ac467c934_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_d4454aa7-13f6-4a17-8350-4b7ac467c934" xlink:to="loc_us-gaap_SegmentDomain_d4454aa7-13f6-4a17-8350-4b7ac467c934_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_9711b921-b57d-46bc-9479-85febd59978f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_d4454aa7-13f6-4a17-8350-4b7ac467c934" xlink:to="loc_us-gaap_SegmentDomain_9711b921-b57d-46bc-9479-85febd59978f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_RailroadMember_6c3d6ce2-1c0d-42bb-9ee4-e0bbc4aeb544" xlink:href="fip-20260331.xsd#fip_RailroadMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_9711b921-b57d-46bc-9479-85febd59978f" xlink:to="loc_fip_RailroadMember_6c3d6ce2-1c0d-42bb-9ee4-e0bbc4aeb544" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_JeffersonTerminalMember_9201cfb4-bf1d-4c42-92d3-4d103a0e7ef5" xlink:href="fip-20260331.xsd#fip_JeffersonTerminalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_9711b921-b57d-46bc-9479-85febd59978f" xlink:to="loc_fip_JeffersonTerminalMember_9201cfb4-bf1d-4c42-92d3-4d103a0e7ef5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_RapaunoMember_827d2ed9-faeb-4e40-bb8f-5e51fe8eca96" xlink:href="fip-20260331.xsd#fip_RapaunoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_9711b921-b57d-46bc-9479-85febd59978f" xlink:to="loc_fip_RapaunoMember_827d2ed9-faeb-4e40-bb8f-5e51fe8eca96" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_PowerAndGasMember_33f7485f-5672-4523-9edc-cd401b3ba5ea" xlink:href="fip-20260331.xsd#fip_PowerAndGasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_9711b921-b57d-46bc-9479-85febd59978f" xlink:to="loc_fip_PowerAndGasMember_33f7485f-5672-4523-9edc-cd401b3ba5ea" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_SustainabilityMember_f9c3a9e4-cf6b-4d98-840e-16bff82de271" xlink:href="fip-20260331.xsd#fip_SustainabilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_9711b921-b57d-46bc-9479-85febd59978f" xlink:to="loc_fip_SustainabilityMember_f9c3a9e4-cf6b-4d98-840e-16bff82de271" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_97dc4490-592d-4ae3-895f-337c37a91a30" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_201a32c7-1dcd-45b2-851d-5b1084e79651" xlink:to="loc_srt_ConsolidationItemsAxis_97dc4490-592d-4ae3-895f-337c37a91a30" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_97dc4490-592d-4ae3-895f-337c37a91a30_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_97dc4490-592d-4ae3-895f-337c37a91a30" xlink:to="loc_srt_ConsolidationItemsDomain_97dc4490-592d-4ae3-895f-337c37a91a30_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_9628a1d1-320d-4cfa-b934-ade3a4ec6866" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_97dc4490-592d-4ae3-895f-337c37a91a30" xlink:to="loc_srt_ConsolidationItemsDomain_9628a1d1-320d-4cfa-b934-ade3a4ec6866" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_2b03d77f-e87c-4538-9afe-c6d5157b6bb8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_9628a1d1-320d-4cfa-b934-ade3a4ec6866" xlink:to="loc_us-gaap_OperatingSegmentsMember_2b03d77f-e87c-4538-9afe-c6d5157b6bb8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_e08d466a-d749-43a1-9e16-af668c6eb277" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CorporateNonSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_9628a1d1-320d-4cfa-b934-ade3a4ec6866" xlink:to="loc_us-gaap_CorporateNonSegmentMember_e08d466a-d749-43a1-9e16-af668c6eb277" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_70a98a08-847e-4566-ae9d-15998f91da0f" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_201a32c7-1dcd-45b2-851d-5b1084e79651" xlink:to="loc_srt_ProductOrServiceAxis_70a98a08-847e-4566-ae9d-15998f91da0f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_70a98a08-847e-4566-ae9d-15998f91da0f_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_70a98a08-847e-4566-ae9d-15998f91da0f" xlink:to="loc_srt_ProductsAndServicesDomain_70a98a08-847e-4566-ae9d-15998f91da0f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_19653abd-c185-4af5-be00-001be52bee35" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_70a98a08-847e-4566-ae9d-15998f91da0f" xlink:to="loc_srt_ProductsAndServicesDomain_19653abd-c185-4af5-be00-001be52bee35" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_InfrastructureMember_91234db5-d1ce-46c9-8fb6-a0969d6dd01e" xlink:href="fip-20260331.xsd#fip_InfrastructureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_19653abd-c185-4af5-be00-001be52bee35" xlink:to="loc_fip_InfrastructureMember_91234db5-d1ce-46c9-8fb6-a0969d6dd01e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_7d5a0bbe-171b-4488-b8e1-33561cae8f08" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_201a32c7-1dcd-45b2-851d-5b1084e79651" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_7d5a0bbe-171b-4488-b8e1-33561cae8f08" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_7d5a0bbe-171b-4488-b8e1-33561cae8f08_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_7d5a0bbe-171b-4488-b8e1-33561cae8f08" xlink:to="loc_us-gaap_EquityComponentDomain_7d5a0bbe-171b-4488-b8e1-33561cae8f08_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_ebaf0d5b-e3e9-490e-90ce-e5b572d0be36" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_7d5a0bbe-171b-4488-b8e1-33561cae8f08" xlink:to="loc_us-gaap_EquityComponentDomain_ebaf0d5b-e3e9-490e-90ce-e5b572d0be36" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestMember_654c021d-be41-4d0e-88df-4722250c337d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_ebaf0d5b-e3e9-490e-90ce-e5b572d0be36" xlink:to="loc_us-gaap_NoncontrollingInterestMember_654c021d-be41-4d0e-88df-4722250c337d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesAbstract_430b388b-aa0a-4f5f-8bc7-4e220e169cf4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenuesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_205dbca7-fb1c-433c-9da0-ac35f444bbaa" xlink:to="loc_us-gaap_RevenuesAbstract_430b388b-aa0a-4f5f-8bc7-4e220e169cf4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_3f008c3f-ab9e-4ed4-bb58-9ac1d35cee1c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_430b388b-aa0a-4f5f-8bc7-4e220e169cf4" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_3f008c3f-ab9e-4ed4-bb58-9ac1d35cee1c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpensesAbstract_e6e1bfb5-c4b6-400d-afe1-4a7c55f7c44a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingExpensesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_205dbca7-fb1c-433c-9da0-ac35f444bbaa" xlink:to="loc_us-gaap_OperatingExpensesAbstract_e6e1bfb5-c4b6-400d-afe1-4a7c55f7c44a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCostAndExpenseOperating_7fbdd495-644a-4d40-97b6-44dcf6a9aef3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherCostAndExpenseOperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_e6e1bfb5-c4b6-400d-afe1-4a7c55f7c44a" xlink:to="loc_us-gaap_OtherCostAndExpenseOperating_7fbdd495-644a-4d40-97b6-44dcf6a9aef3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_ec6bb73c-ed4d-4635-8e12-97ae9ec6ea11" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_e6e1bfb5-c4b6-400d-afe1-4a7c55f7c44a" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_ec6bb73c-ed4d-4635-8e12-97ae9ec6ea11" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_10060a02-3798-4754-841b-4bc4c4287d81" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_e6e1bfb5-c4b6-400d-afe1-4a7c55f7c44a" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_10060a02-3798-4754-841b-4bc4c4287d81" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ManagementFeeExpense_bb9b003c-e28b-43ea-897a-20a067f772a8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ManagementFeeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_e6e1bfb5-c4b6-400d-afe1-4a7c55f7c44a" xlink:to="loc_us-gaap_ManagementFeeExpense_bb9b003c-e28b-43ea-897a-20a067f772a8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_9eb87095-868c-412a-8393-345fb70f84ca" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_e6e1bfb5-c4b6-400d-afe1-4a7c55f7c44a" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_9eb87095-868c-412a-8393-345fb70f84ca" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetImpairmentCharges_198ee838-ef80-4eae-97f3-e02dd213b186" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetImpairmentCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_e6e1bfb5-c4b6-400d-afe1-4a7c55f7c44a" xlink:to="loc_us-gaap_AssetImpairmentCharges_198ee838-ef80-4eae-97f3-e02dd213b186" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAndExpenses_a3a6086a-d31a-4693-8969-cd2af3ba21a4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostsAndExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_e6e1bfb5-c4b6-400d-afe1-4a7c55f7c44a" xlink:to="loc_us-gaap_CostsAndExpenses_a3a6086a-d31a-4693-8969-cd2af3ba21a4" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherIncomeAndExpensesAbstract_16b7ed8f-c2a0-4f97-90c1-766619791481" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherIncomeAndExpensesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_205dbca7-fb1c-433c-9da0-ac35f444bbaa" xlink:to="loc_us-gaap_OtherIncomeAndExpensesAbstract_16b7ed8f-c2a0-4f97-90c1-766619791481" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromEquityMethodInvestments_260c4cf3-f90f-44c0-ac54-53f2676d68c3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromEquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherIncomeAndExpensesAbstract_16b7ed8f-c2a0-4f97-90c1-766619791481" xlink:to="loc_us-gaap_IncomeLossFromEquityMethodInvestments_260c4cf3-f90f-44c0-ac54-53f2676d68c3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSaleOfPropertyPlantEquipment_30505275-6f14-4411-b7d0-9a36a7421f65" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainLossOnSaleOfPropertyPlantEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherIncomeAndExpensesAbstract_16b7ed8f-c2a0-4f97-90c1-766619791481" xlink:to="loc_us-gaap_GainLossOnSaleOfPropertyPlantEquipment_30505275-6f14-4411-b7d0-9a36a7421f65" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseNet_922e3b4e-0017-4b91-89e1-4769627cfdb1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeExpenseNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherIncomeAndExpensesAbstract_16b7ed8f-c2a0-4f97-90c1-766619791481" xlink:to="loc_us-gaap_InterestIncomeExpenseNet_922e3b4e-0017-4b91-89e1-4769627cfdb1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_eb61920e-b398-49a9-98b0-5d8b1dd223bb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherIncomeAndExpensesAbstract_16b7ed8f-c2a0-4f97-90c1-766619791481" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_eb61920e-b398-49a9-98b0-5d8b1dd223bb" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_d831c367-2903-44e3-a903-cd0f06d29e75" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherIncomeAndExpensesAbstract_16b7ed8f-c2a0-4f97-90c1-766619791481" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_d831c367-2903-44e3-a903-cd0f06d29e75" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_5d03a023-f0d3-4058-b0cd-b0e898544c5a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_205dbca7-fb1c-433c-9da0-ac35f444bbaa" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_5d03a023-f0d3-4058-b0cd-b0e898544c5a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_23798a2b-696e-4a9a-8890-9eb9d2a26319" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_205dbca7-fb1c-433c-9da0-ac35f444bbaa" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_23798a2b-696e-4a9a-8890-9eb9d2a26319" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_de6fb907-761b-4b24-a9e4-ce43ceaf7708" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_205dbca7-fb1c-433c-9da0-ac35f444bbaa" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_de6fb907-761b-4b24-a9e4-ce43ceaf7708" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_a30156ca-1dd3-49ea-aa5a-dfb4524c8e8b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_205dbca7-fb1c-433c-9da0-ac35f444bbaa" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_a30156ca-1dd3-49ea-aa5a-dfb4524c8e8b" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockDividendsIncomeStatementImpact_b0aad175-88d1-4f22-bb68-cd1d709c2dbd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockDividendsIncomeStatementImpact"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_205dbca7-fb1c-433c-9da0-ac35f444bbaa" xlink:to="loc_us-gaap_PreferredStockDividendsIncomeStatementImpact_b0aad175-88d1-4f22-bb68-cd1d709c2dbd" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPreferredStock_b5d9e3ce-89a9-4304-a206-f93105d4f405" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DividendsPreferredStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_205dbca7-fb1c-433c-9da0-ac35f444bbaa" xlink:to="loc_us-gaap_DividendsPreferredStock_b5d9e3ce-89a9-4304-a206-f93105d4f405" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperations_02da63f4-1f8e-4a50-aac6-529a05679ecf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_205dbca7-fb1c-433c-9da0-ac35f444bbaa" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperations_02da63f4-1f8e-4a50-aac6-529a05679ecf" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonrecurringIncomeExpense_5fb804a2-ca4c-446e-ac28-63352c8c633b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherNonrecurringIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_205dbca7-fb1c-433c-9da0-ac35f444bbaa" xlink:to="loc_us-gaap_OtherNonrecurringIncomeExpense_5fb804a2-ca4c-446e-ac28-63352c8c633b" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_d0f50c61-e9f0-4dd1-8095-80f344fbcc47" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_205dbca7-fb1c-433c-9da0-ac35f444bbaa" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_d0f50c61-e9f0-4dd1-8095-80f344fbcc47" xlink:type="arc" order="11"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/SEGMENTINFORMATIONReconciliationofAdjustedEBITDAtoNetLossDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#SEGMENTINFORMATIONReconciliationofAdjustedEBITDAtoNetLossDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/SEGMENTINFORMATIONReconciliationofAdjustedEBITDAtoNetLossDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_af124943-0a86-4f51-adf4-7679de13b462" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_2dee6f0a-3787-4a89-b710-586d574f1012" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_af124943-0a86-4f51-adf4-7679de13b462" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_2dee6f0a-3787-4a89-b710-586d574f1012" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_dbdb24b1-894f-491d-b048-8b13a06b31b6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_2dee6f0a-3787-4a89-b710-586d574f1012" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_dbdb24b1-894f-491d-b048-8b13a06b31b6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_dbdb24b1-894f-491d-b048-8b13a06b31b6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_dbdb24b1-894f-491d-b048-8b13a06b31b6" xlink:to="loc_us-gaap_SegmentDomain_dbdb24b1-894f-491d-b048-8b13a06b31b6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_58e281f7-f6d2-4f7f-ab3c-aecdbb7f7037" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_dbdb24b1-894f-491d-b048-8b13a06b31b6" xlink:to="loc_us-gaap_SegmentDomain_58e281f7-f6d2-4f7f-ab3c-aecdbb7f7037" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_RailroadMember_758de6cc-bd62-4e17-a4a6-f5144640a6b6" xlink:href="fip-20260331.xsd#fip_RailroadMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_58e281f7-f6d2-4f7f-ab3c-aecdbb7f7037" xlink:to="loc_fip_RailroadMember_758de6cc-bd62-4e17-a4a6-f5144640a6b6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_JeffersonTerminalMember_35235b1e-6a18-42b9-a18c-46d1f2246a6f" xlink:href="fip-20260331.xsd#fip_JeffersonTerminalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_58e281f7-f6d2-4f7f-ab3c-aecdbb7f7037" xlink:to="loc_fip_JeffersonTerminalMember_35235b1e-6a18-42b9-a18c-46d1f2246a6f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_RapaunoMember_b39cfa00-b4b9-4ede-8355-980e755057a2" xlink:href="fip-20260331.xsd#fip_RapaunoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_58e281f7-f6d2-4f7f-ab3c-aecdbb7f7037" xlink:to="loc_fip_RapaunoMember_b39cfa00-b4b9-4ede-8355-980e755057a2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_PowerAndGasMember_cc22935e-1c33-402b-9bfb-0cc3e4c4ac61" xlink:href="fip-20260331.xsd#fip_PowerAndGasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_58e281f7-f6d2-4f7f-ab3c-aecdbb7f7037" xlink:to="loc_fip_PowerAndGasMember_cc22935e-1c33-402b-9bfb-0cc3e4c4ac61" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_SustainabilityMember_079ff916-5520-47d9-ba98-0aa0bef3506c" xlink:href="fip-20260331.xsd#fip_SustainabilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_58e281f7-f6d2-4f7f-ab3c-aecdbb7f7037" xlink:to="loc_fip_SustainabilityMember_079ff916-5520-47d9-ba98-0aa0bef3506c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_4d398584-ea0e-4143-b392-ce109cdb8957" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_2dee6f0a-3787-4a89-b710-586d574f1012" xlink:to="loc_srt_ConsolidationItemsAxis_4d398584-ea0e-4143-b392-ce109cdb8957" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_4d398584-ea0e-4143-b392-ce109cdb8957_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_4d398584-ea0e-4143-b392-ce109cdb8957" xlink:to="loc_srt_ConsolidationItemsDomain_4d398584-ea0e-4143-b392-ce109cdb8957_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_6eb10b2c-c431-4940-847d-126b5cd496fc" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_4d398584-ea0e-4143-b392-ce109cdb8957" xlink:to="loc_srt_ConsolidationItemsDomain_6eb10b2c-c431-4940-847d-126b5cd496fc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_7e287dae-484d-4bcf-b1f1-d8ac6a415d0f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_6eb10b2c-c431-4940-847d-126b5cd496fc" xlink:to="loc_us-gaap_OperatingSegmentsMember_7e287dae-484d-4bcf-b1f1-d8ac6a415d0f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_90cc2196-22dd-4ecd-8d94-bf6e8591b0d8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CorporateNonSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_6eb10b2c-c431-4940-847d-126b5cd496fc" xlink:to="loc_us-gaap_CorporateNonSegmentMember_90cc2196-22dd-4ecd-8d94-bf6e8591b0d8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_AdjustedNetIncomeLoss_50106949-b27b-4607-8b35-b09818f407f2" xlink:href="fip-20260331.xsd#fip_AdjustedNetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_af124943-0a86-4f51-adf4-7679de13b462" xlink:to="loc_fip_AdjustedNetIncomeLoss_50106949-b27b-4607-8b35-b09818f407f2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_AdjustedNetIncomeLossAttributableToNonControllingInterest_fbf815c5-9e7a-4e3a-8552-5ae9199a1183" xlink:href="fip-20260331.xsd#fip_AdjustedNetIncomeLossAttributableToNonControllingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_af124943-0a86-4f51-adf4-7679de13b462" xlink:to="loc_fip_AdjustedNetIncomeLossAttributableToNonControllingInterest_fbf815c5-9e7a-4e3a-8552-5ae9199a1183" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromEquityMethodInvestments_d742905d-3702-4213-b46c-3b10eea76ed7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromEquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_af124943-0a86-4f51-adf4-7679de13b462" xlink:to="loc_us-gaap_IncomeLossFromEquityMethodInvestments_d742905d-3702-4213-b46c-3b10eea76ed7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetPeriodicDefinedBenefitsExpenseReversalOfExpenseExcludingServiceCostComponent_ead33209-20ec-4848-a347-94b069fbf20f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetPeriodicDefinedBenefitsExpenseReversalOfExpenseExcludingServiceCostComponent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_af124943-0a86-4f51-adf4-7679de13b462" xlink:to="loc_us-gaap_NetPeriodicDefinedBenefitsExpenseReversalOfExpenseExcludingServiceCostComponent_ead33209-20ec-4848-a347-94b069fbf20f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RedeemablePreferredStockDividends_a351c6c8-ae0d-44cd-b60b-05073c631e81" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RedeemablePreferredStockDividends"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_af124943-0a86-4f51-adf4-7679de13b462" xlink:to="loc_us-gaap_RedeemablePreferredStockDividends_a351c6c8-ae0d-44cd-b60b-05073c631e81" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockDividendsAndOtherAdjustments_d15959e0-4710-4a38-8a24-97d47620725c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockDividendsAndOtherAdjustments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_af124943-0a86-4f51-adf4-7679de13b462" xlink:to="loc_us-gaap_PreferredStockDividendsAndOtherAdjustments_d15959e0-4710-4a38-8a24-97d47620725c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_IncomeLossFromEquityMethodInvestmentsProRataShare_181967a7-b6f5-4430-8c22-9e17fc558d0b" xlink:href="fip-20260331.xsd#fip_IncomeLossFromEquityMethodInvestmentsProRataShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_af124943-0a86-4f51-adf4-7679de13b462" xlink:to="loc_fip_IncomeLossFromEquityMethodInvestmentsProRataShare_181967a7-b6f5-4430-8c22-9e17fc558d0b" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpense_2348d52a-dd40-4eeb-8218-2ad945baeae7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_af124943-0a86-4f51-adf4-7679de13b462" xlink:to="loc_us-gaap_InterestExpense_2348d52a-dd40-4eeb-8218-2ad945baeae7" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherDepreciationAndAmortization_149dcfa0-5cb0-426a-8d5e-0da6afc01441" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_af124943-0a86-4f51-adf4-7679de13b462" xlink:to="loc_us-gaap_OtherDepreciationAndAmortization_149dcfa0-5cb0-426a-8d5e-0da6afc01441" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_IncentiveIncomeAllocated_7a3216a1-de25-4508-871e-33dddabb07dc" xlink:href="fip-20260331.xsd#fip_IncentiveIncomeAllocated"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_af124943-0a86-4f51-adf4-7679de13b462" xlink:to="loc_fip_IncentiveIncomeAllocated_7a3216a1-de25-4508-871e-33dddabb07dc" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetImpairmentCharges_ad7b2083-b7bf-4c94-bb64-8a5300f89152" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetImpairmentCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_af124943-0a86-4f51-adf4-7679de13b462" xlink:to="loc_us-gaap_AssetImpairmentCharges_ad7b2083-b7bf-4c94-bb64-8a5300f89152" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1_6ddf6f34-defc-442f-8f78-d0abd29ff6d1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_af124943-0a86-4f51-adf4-7679de13b462" xlink:to="loc_us-gaap_ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1_6ddf6f34-defc-442f-8f78-d0abd29ff6d1" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_GainsLossesOnExtinguishmentOrRestructuringOfDebt_4ff0b5b4-abd8-49c6-bf58-b708ef7b3587" xlink:href="fip-20260331.xsd#fip_GainsLossesOnExtinguishmentOrRestructuringOfDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_af124943-0a86-4f51-adf4-7679de13b462" xlink:to="loc_fip_GainsLossesOnExtinguishmentOrRestructuringOfDebt_4ff0b5b4-abd8-49c6-bf58-b708ef7b3587" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_f3b89b04-5b48-4f07-b09e-5054460d4e6d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_af124943-0a86-4f51-adf4-7679de13b462" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_f3b89b04-5b48-4f07-b09e-5054460d4e6d" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_8bc8bf81-5fbf-41c9-916e-7e785ae82cc5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_af124943-0a86-4f51-adf4-7679de13b462" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_8bc8bf81-5fbf-41c9-916e-7e785ae82cc5" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_a56fe1dc-43ec-4dde-ace1-c429321b88e8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_af124943-0a86-4f51-adf4-7679de13b462" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_a56fe1dc-43ec-4dde-ace1-c429321b88e8" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonrecurringIncomeExpense_e0044848-2ebc-4328-8258-3d0737fd9062" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherNonrecurringIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_af124943-0a86-4f51-adf4-7679de13b462" xlink:to="loc_us-gaap_OtherNonrecurringIncomeExpense_e0044848-2ebc-4328-8258-3d0737fd9062" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperations_07ec0fae-5b46-4230-a968-2e20ae9cf0ca" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_af124943-0a86-4f51-adf4-7679de13b462" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperations_07ec0fae-5b46-4230-a968-2e20ae9cf0ca" xlink:type="arc" order="17"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/SEGMENTINFORMATIONBalanceSheetDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#SEGMENTINFORMATIONBalanceSheetDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/SEGMENTINFORMATIONBalanceSheetDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_b4981ae0-aaa8-4385-a6bc-f02fdc231fab" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_4dce268f-64c1-427c-ac4c-16ca41393a9b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_b4981ae0-aaa8-4385-a6bc-f02fdc231fab" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_4dce268f-64c1-427c-ac4c-16ca41393a9b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_29296b3f-150a-4885-8e84-179e8ce77493" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_4dce268f-64c1-427c-ac4c-16ca41393a9b" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_29296b3f-150a-4885-8e84-179e8ce77493" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_29296b3f-150a-4885-8e84-179e8ce77493_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_29296b3f-150a-4885-8e84-179e8ce77493" xlink:to="loc_us-gaap_SegmentDomain_29296b3f-150a-4885-8e84-179e8ce77493_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_97bbbcd8-2921-4645-9c03-d41fe9fad139" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_29296b3f-150a-4885-8e84-179e8ce77493" xlink:to="loc_us-gaap_SegmentDomain_97bbbcd8-2921-4645-9c03-d41fe9fad139" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_RailroadMember_f91f5943-62d6-4046-ad3b-93bdb798d199" xlink:href="fip-20260331.xsd#fip_RailroadMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_97bbbcd8-2921-4645-9c03-d41fe9fad139" xlink:to="loc_fip_RailroadMember_f91f5943-62d6-4046-ad3b-93bdb798d199" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_JeffersonTerminalMember_e8b82565-60e6-4b8a-a0c7-22b60bc1c283" xlink:href="fip-20260331.xsd#fip_JeffersonTerminalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_97bbbcd8-2921-4645-9c03-d41fe9fad139" xlink:to="loc_fip_JeffersonTerminalMember_e8b82565-60e6-4b8a-a0c7-22b60bc1c283" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_RapaunoMember_69414e19-8f1d-41a5-b3a8-85f3ae984df3" xlink:href="fip-20260331.xsd#fip_RapaunoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_97bbbcd8-2921-4645-9c03-d41fe9fad139" xlink:to="loc_fip_RapaunoMember_69414e19-8f1d-41a5-b3a8-85f3ae984df3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_PowerAndGasMember_2aa4499e-409e-4774-9603-cdba95cecbb9" xlink:href="fip-20260331.xsd#fip_PowerAndGasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_97bbbcd8-2921-4645-9c03-d41fe9fad139" xlink:to="loc_fip_PowerAndGasMember_2aa4499e-409e-4774-9603-cdba95cecbb9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_SustainabilityMember_c753ee64-b552-47c7-8627-953866cc702a" xlink:href="fip-20260331.xsd#fip_SustainabilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_97bbbcd8-2921-4645-9c03-d41fe9fad139" xlink:to="loc_fip_SustainabilityMember_c753ee64-b552-47c7-8627-953866cc702a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_cbec16a7-638c-45c7-b4a7-10d53b968637" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_4dce268f-64c1-427c-ac4c-16ca41393a9b" xlink:to="loc_srt_ConsolidationItemsAxis_cbec16a7-638c-45c7-b4a7-10d53b968637" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_cbec16a7-638c-45c7-b4a7-10d53b968637_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_cbec16a7-638c-45c7-b4a7-10d53b968637" xlink:to="loc_srt_ConsolidationItemsDomain_cbec16a7-638c-45c7-b4a7-10d53b968637_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_71a17657-383d-4aa6-a969-388c1cee7ddf" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_cbec16a7-638c-45c7-b4a7-10d53b968637" xlink:to="loc_srt_ConsolidationItemsDomain_71a17657-383d-4aa6-a969-388c1cee7ddf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_65de51ce-394a-4796-8ec4-3ae5885f0eb3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_71a17657-383d-4aa6-a969-388c1cee7ddf" xlink:to="loc_us-gaap_OperatingSegmentsMember_65de51ce-394a-4796-8ec4-3ae5885f0eb3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_772fc7ab-8ef5-4613-87bf-6dc217f1a851" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CorporateNonSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_71a17657-383d-4aa6-a969-388c1cee7ddf" xlink:to="loc_us-gaap_CorporateNonSegmentMember_772fc7ab-8ef5-4613-87bf-6dc217f1a851" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_0d4bd876-2bc1-40a1-af03-c748cbcff74e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_b4981ae0-aaa8-4385-a6bc-f02fdc231fab" xlink:to="loc_us-gaap_AssetsCurrent_0d4bd876-2bc1-40a1-af03-c748cbcff74e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsNoncurrent_450201f0-dab4-4c63-b0f1-180382b8e718" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_b4981ae0-aaa8-4385-a6bc-f02fdc231fab" xlink:to="loc_us-gaap_AssetsNoncurrent_450201f0-dab4-4c63-b0f1-180382b8e718" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_b283972c-73db-4993-a4ba-2ac8e8dcdfc0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_b4981ae0-aaa8-4385-a6bc-f02fdc231fab" xlink:to="loc_us-gaap_Assets_b283972c-73db-4993-a4ba-2ac8e8dcdfc0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_28be85d8-30b3-429d-80a0-cafd6664617e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_b4981ae0-aaa8-4385-a6bc-f02fdc231fab" xlink:to="loc_us-gaap_LongTermDebt_28be85d8-30b3-429d-80a0-cafd6664617e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_68a7b68a-ec4e-46a4-bfae-aef08570474f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_b4981ae0-aaa8-4385-a6bc-f02fdc231fab" xlink:to="loc_us-gaap_LiabilitiesCurrent_68a7b68a-ec4e-46a4-bfae-aef08570474f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesNoncurrent_423c73f6-5f32-487c-9990-2d0b202eccf2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_b4981ae0-aaa8-4385-a6bc-f02fdc231fab" xlink:to="loc_us-gaap_LiabilitiesNoncurrent_423c73f6-5f32-487c-9990-2d0b202eccf2" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_69338c03-484d-4c87-97c5-6e951d0734c5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Liabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_b4981ae0-aaa8-4385-a6bc-f02fdc231fab" xlink:to="loc_us-gaap_Liabilities_69338c03-484d-4c87-97c5-6e951d0734c5" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityCarryingAmountAttributableToParent_93dced80-f86d-47d2-b648-5707cd0209cb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquityCarryingAmountAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_b4981ae0-aaa8-4385-a6bc-f02fdc231fab" xlink:to="loc_us-gaap_TemporaryEquityCarryingAmountAttributableToParent_93dced80-f86d-47d2-b648-5707cd0209cb" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MembersEquityAbstract_0b9f4909-0716-420f-8f34-9ffa8242fff8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MembersEquityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_b4981ae0-aaa8-4385-a6bc-f02fdc231fab" xlink:to="loc_us-gaap_MembersEquityAbstract_0b9f4909-0716-420f-8f34-9ffa8242fff8" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MembersEquityAttributableToNoncontrollingInterest_d34fbe99-3e96-445c-bc60-207017470409" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MembersEquityAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MembersEquityAbstract_0b9f4909-0716-420f-8f34-9ffa8242fff8" xlink:to="loc_us-gaap_MembersEquityAttributableToNoncontrollingInterest_d34fbe99-3e96-445c-bc60-207017470409" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest_d4afb601-e59a-4f90-b8ba-d18c4ece905b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MembersEquityAbstract_0b9f4909-0716-420f-8f34-9ffa8242fff8" xlink:to="loc_us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest_d4afb601-e59a-4f90-b8ba-d18c4ece905b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_b6297690-2266-4add-bda5-9e5b36f0ee40" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_b4981ae0-aaa8-4385-a6bc-f02fdc231fab" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_b6297690-2266-4add-bda5-9e5b36f0ee40" xlink:type="arc" order="9"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/REDEEMABLEPREFERREDSTOCKDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#REDEEMABLEPREFERREDSTOCKDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/REDEEMABLEPREFERREDSTOCKDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_019dfa28-05a0-75fb-bb96-e7aace0b6741" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_019dfa28-05a0-70da-9119-3f3c6ff446e0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_019dfa28-05a0-75fb-bb96-e7aace0b6741" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_019dfa28-05a0-70da-9119-3f3c6ff446e0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019dfa28-05a0-7aae-90e6-6166bcc8fd89" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_019dfa28-05a0-70da-9119-3f3c6ff446e0" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019dfa28-05a0-7aae-90e6-6166bcc8fd89" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019dfa28-05a0-7aae-90e6-6166bcc8fd89_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019dfa28-05a0-7aae-90e6-6166bcc8fd89" xlink:to="loc_us-gaap_ClassOfStockDomain_019dfa28-05a0-7aae-90e6-6166bcc8fd89_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019dfa28-05a0-7a78-891c-7a091f910080" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019dfa28-05a0-7aae-90e6-6166bcc8fd89" xlink:to="loc_us-gaap_ClassOfStockDomain_019dfa28-05a0-7a78-891c-7a091f910080" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesBPreferredStockMember_019dfa28-05a0-7d51-8a98-bf389db6929b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesBPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019dfa28-05a0-7a78-891c-7a091f910080" xlink:to="loc_us-gaap_SeriesBPreferredStockMember_019dfa28-05a0-7d51-8a98-bf389db6929b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_SeriesAPreferredStockRailcoMember_019dfa28-05a0-7ed7-8bb9-9b86abd8f9ba" xlink:href="fip-20260331.xsd#fip_SeriesAPreferredStockRailcoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019dfa28-05a0-7a78-891c-7a091f910080" xlink:to="loc_fip_SeriesAPreferredStockRailcoMember_019dfa28-05a0-7ed7-8bb9-9b86abd8f9ba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_TemporaryEquityCumulativeDividendsPaidInKind_019dfa28-05a0-7b0d-9a1e-7b1ef1d33801" xlink:href="fip-20260331.xsd#fip_TemporaryEquityCumulativeDividendsPaidInKind"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019dfa28-05a0-75fb-bb96-e7aace0b6741" xlink:to="loc_fip_TemporaryEquityCumulativeDividendsPaidInKind_019dfa28-05a0-7b0d-9a1e-7b1ef1d33801" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_TemporaryEquityRedemptionValueRedeemedDueToChangeInControl_019dfa28-05a0-79ea-a0fb-407907926034" xlink:href="fip-20260331.xsd#fip_TemporaryEquityRedemptionValueRedeemedDueToChangeInControl"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019dfa28-05a0-75fb-bb96-e7aace0b6741" xlink:to="loc_fip_TemporaryEquityRedemptionValueRedeemedDueToChangeInControl_019dfa28-05a0-79ea-a0fb-407907926034" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_TemporaryEquityCommonStockSharesIssuedIfConverted_019dfa28-05a0-7e07-8418-686f87349068" xlink:href="fip-20260331.xsd#fip_TemporaryEquityCommonStockSharesIssuedIfConverted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019dfa28-05a0-75fb-bb96-e7aace0b6741" xlink:to="loc_fip_TemporaryEquityCommonStockSharesIssuedIfConverted_019dfa28-05a0-7e07-8418-686f87349068" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_TemporaryEquityDividendsPaid_019dfa28-05a0-7fc6-9a59-3ca33a1f897f" xlink:href="fip-20260331.xsd#fip_TemporaryEquityDividendsPaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019dfa28-05a0-75fb-bb96-e7aace0b6741" xlink:to="loc_fip_TemporaryEquityDividendsPaid_019dfa28-05a0-7fc6-9a59-3ca33a1f897f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityAccretionOfDividends_019dfa28-05a0-72a5-b794-1e3ea8e2c2e5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquityAccretionOfDividends"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019dfa28-05a0-75fb-bb96-e7aace0b6741" xlink:to="loc_us-gaap_TemporaryEquityAccretionOfDividends_019dfa28-05a0-72a5-b794-1e3ea8e2c2e5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockRedemptionPricePerShare_019dfa28-05a0-7692-813e-e2f0d86c46de" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockRedemptionPricePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019dfa28-05a0-75fb-bb96-e7aace0b6741" xlink:to="loc_us-gaap_PreferredStockRedemptionPricePerShare_019dfa28-05a0-7692-813e-e2f0d86c46de" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/EARNINGSPERSHAREANDEQUITYNarrativeDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#EARNINGSPERSHAREANDEQUITYNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/EARNINGSPERSHAREANDEQUITYNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_019dfa27-0e4b-7e9e-b4a4-0addf9bed84d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_019dfa27-0e4b-7dce-8855-9e886c71637f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_019dfa27-0e4b-7e9e-b4a4-0addf9bed84d" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_019dfa27-0e4b-7dce-8855-9e886c71637f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019dfa27-0e4b-7326-ab7c-e48c5d4e7c29" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_019dfa27-0e4b-7dce-8855-9e886c71637f" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019dfa27-0e4b-7326-ab7c-e48c5d4e7c29" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019dfa27-0e4b-7326-ab7c-e48c5d4e7c29_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019dfa27-0e4b-7326-ab7c-e48c5d4e7c29" xlink:to="loc_us-gaap_ClassOfStockDomain_019dfa27-0e4b-7326-ab7c-e48c5d4e7c29_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019dfa27-0e4b-7082-b3e8-9a6f1f9012f7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019dfa27-0e4b-7326-ab7c-e48c5d4e7c29" xlink:to="loc_us-gaap_ClassOfStockDomain_019dfa27-0e4b-7082-b3e8-9a6f1f9012f7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019dfa27-0e4b-7221-8313-1e0359234d09" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019dfa27-0e4b-7082-b3e8-9a6f1f9012f7" xlink:to="loc_us-gaap_CommonStockMember_019dfa27-0e4b-7221-8313-1e0359234d09" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019dfa27-0e4b-7797-b90b-90b5b72260ba" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019dfa27-0e4b-7e9e-b4a4-0addf9bed84d" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019dfa27-0e4b-7797-b90b-90b5b72260ba" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_019dfa27-283a-70ba-bb79-cbdaf1d79894" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019dfa27-0e4b-7e9e-b4a4-0addf9bed84d" xlink:to="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_019dfa27-283a-70ba-bb79-cbdaf1d79894" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_WarrantsOrRightExercisableWeightedAverageRemainingContractualLife_019dfa27-283a-7742-b49e-8acd01af4c34" xlink:href="fip-20260331.xsd#fip_WarrantsOrRightExercisableWeightedAverageRemainingContractualLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019dfa27-0e4b-7e9e-b4a4-0addf9bed84d" xlink:to="loc_fip_WarrantsOrRightExercisableWeightedAverageRemainingContractualLife_019dfa27-283a-7742-b49e-8acd01af4c34" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueOutstanding_019dfa27-283a-7e22-a8ef-f9caf8bba163" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019dfa27-0e4b-7e9e-b4a4-0addf9bed84d" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueOutstanding_019dfa27-283a-7e22-a8ef-f9caf8bba163" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.ftandi.com/role/SUBSEQUENTEVENTSDetails" xlink:type="simple" xlink:href="fip-20260331.xsd#SUBSEQUENTEVENTSDetails"/>
  <link:definitionLink xlink:role="http://www.ftandi.com/role/SUBSEQUENTEVENTSDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventLineItems_019de4b9-a164-794e-ae59-bf9aecf8fa79" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTable_019de4b9-a164-75d6-b0da-1ac0176f8a12" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems_019de4b9-a164-794e-ae59-bf9aecf8fa79" xlink:to="loc_us-gaap_SubsequentEventTable_019de4b9-a164-75d6-b0da-1ac0176f8a12" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019de4b9-a164-7916-a0ab-788902f85fcc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_019de4b9-a164-75d6-b0da-1ac0176f8a12" xlink:to="loc_us-gaap_DebtInstrumentAxis_019de4b9-a164-7916-a0ab-788902f85fcc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019de4b9-a164-7916-a0ab-788902f85fcc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019de4b9-a164-7916-a0ab-788902f85fcc" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019de4b9-a164-7916-a0ab-788902f85fcc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019de4b9-a164-750a-9854-e313fbb1161c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019de4b9-a164-7916-a0ab-788902f85fcc" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019de4b9-a164-750a-9854-e313fbb1161c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_LongRidgeAcquiomLoanIncrementalBorrowingApril2026Member_019de4b9-a164-7214-a0f3-210d755a997e" xlink:href="fip-20260331.xsd#fip_LongRidgeAcquiomLoanIncrementalBorrowingApril2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019de4b9-a164-750a-9854-e313fbb1161c" xlink:to="loc_fip_LongRidgeAcquiomLoanIncrementalBorrowingApril2026Member_019de4b9-a164-7214-a0f3-210d755a997e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019de4b9-a164-7798-a6ff-96b6cb078795" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_019de4b9-a164-75d6-b0da-1ac0176f8a12" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019de4b9-a164-7798-a6ff-96b6cb078795" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019de4b9-a164-7798-a6ff-96b6cb078795_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019de4b9-a164-7798-a6ff-96b6cb078795" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019de4b9-a164-7798-a6ff-96b6cb078795_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019de4b9-a164-7f77-84c0-6a2a2b32e88c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019de4b9-a164-7798-a6ff-96b6cb078795" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019de4b9-a164-7f77-84c0-6a2a2b32e88c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_019de4b9-a164-7b4d-a718-484ff3cf887f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019de4b9-a164-7f77-84c0-6a2a2b32e88c" xlink:to="loc_us-gaap_LineOfCreditMember_019de4b9-a164-7b4d-a718-484ff3cf887f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_019de4b9-a164-7ccc-8435-64ec41fe6c3e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_019de4b9-a164-75d6-b0da-1ac0176f8a12" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_019de4b9-a164-7ccc-8435-64ec41fe6c3e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019de4b9-a164-7ccc-8435-64ec41fe6c3e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019de4b9-a164-7ccc-8435-64ec41fe6c3e" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019de4b9-a164-7ccc-8435-64ec41fe6c3e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019de4b9-a164-7c9c-8eb7-743528ce6ce8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019de4b9-a164-7ccc-8435-64ec41fe6c3e" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019de4b9-a164-7c9c-8eb7-743528ce6ce8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_019de4b9-a164-7c59-a74c-bdc2f057edce" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_019de4b9-a164-7c9c-8eb7-743528ce6ce8" xlink:to="loc_us-gaap_SubsequentEventMember_019de4b9-a164-7c59-a74c-bdc2f057edce" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019de4b9-a164-71cd-8725-baa7c2989037" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_019de4b9-a164-75d6-b0da-1ac0176f8a12" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019de4b9-a164-71cd-8725-baa7c2989037" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_019de4b9-a164-71cd-8725-baa7c2989037_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019de4b9-a164-71cd-8725-baa7c2989037" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_019de4b9-a164-71cd-8725-baa7c2989037_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_019de4b9-a164-7719-9f37-3e3bc32eb77f" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019de4b9-a164-71cd-8725-baa7c2989037" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_019de4b9-a164-7719-9f37-3e3bc32eb77f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_fip_LongRidgeEnergyPowerLLCMember_019de4b9-a164-722a-8b95-550ad35f9820" xlink:href="fip-20260331.xsd#fip_LongRidgeEnergyPowerLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_019de4b9-a164-7719-9f37-3e3bc32eb77f" xlink:to="loc_fip_LongRidgeEnergyPowerLLCMember_019de4b9-a164-722a-8b95-550ad35f9820" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_019de4b9-a164-7df8-8952-2cbf83a84dd3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019de4b9-a164-794e-ae59-bf9aecf8fa79" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_019de4b9-a164-7df8-8952-2cbf83a84dd3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromDivestitureOfInterestInSubsidiariesAndAffiliates_019de4b9-a164-7ec0-aa4d-b75a9cfc200e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromDivestitureOfInterestInSubsidiariesAndAffiliates"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019de4b9-a164-794e-ae59-bf9aecf8fa79" xlink:to="loc_us-gaap_ProceedsFromDivestitureOfInterestInSubsidiariesAndAffiliates_019de4b9-a164-7ec0-aa4d-b75a9cfc200e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockDividendsPerShareDeclared_019de4b9-a164-7f77-86b8-abdf3a08c85d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockDividendsPerShareDeclared"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019de4b9-a164-794e-ae59-bf9aecf8fa79" xlink:to="loc_us-gaap_CommonStockDividendsPerShareDeclared_019de4b9-a164-7f77-86b8-abdf3a08c85d" xlink:type="arc" order="2"/>
  </link:definitionLink>
</link:linkbase>
