<?xml version="1.0" encoding="us-ascii"?>
<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:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/notAll" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#notAll" xlink:type="simple" />
  <link:roleRef roleURI="http://indigoacquisitioncorp.com/20260331/role/OrganizationandBusinessOperationsDetails" xlink:href="inacu-20260331.xsd#OrganizationandBusinessOperationsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://indigoacquisitioncorp.com/20260331/role/SummaryofSignificantAccountingPoliciesScheduleofBasicandDilutedNetIncomePerOrdinaryShareDetails" xlink:href="inacu-20260331.xsd#SummaryofSignificantAccountingPoliciesScheduleofBasicandDilutedNetIncomePerOrdinaryShareDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://indigoacquisitioncorp.com/20260331/role/RelatedPartiesDetails" xlink:href="inacu-20260331.xsd#RelatedPartiesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://indigoacquisitioncorp.com/20260331/role/Cover" xlink:href="inacu-20260331.xsd#Cover" xlink:type="simple" />
  <link:roleRef roleURI="http://indigoacquisitioncorp.com/20260331/role/FairValueMeasurementsScheduleofAssetsthatareMeasuredatFairValueDetails" xlink:href="inacu-20260331.xsd#FairValueMeasurementsScheduleofAssetsthatareMeasuredatFairValueDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://indigoacquisitioncorp.com/20260331/role/ShareholdersDeficitDetails" xlink:href="inacu-20260331.xsd#ShareholdersDeficitDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://indigoacquisitioncorp.com/20260331/role/CondensedStatementsofOperationsUnaudited" xlink:href="inacu-20260331.xsd#CondensedStatementsofOperationsUnaudited" xlink:type="simple" />
  <link:roleRef roleURI="http://indigoacquisitioncorp.com/20260331/role/InitialPublicOfferingDetails" xlink:href="inacu-20260331.xsd#InitialPublicOfferingDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://indigoacquisitioncorp.com/20260331/role/PrivatePlacementsDetails" xlink:href="inacu-20260331.xsd#PrivatePlacementsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://indigoacquisitioncorp.com/20260331/role/CondensedStatementsofChangesinShareholdersDeficitUnauditedParentheticals" xlink:href="inacu-20260331.xsd#CondensedStatementsofChangesinShareholdersDeficitUnauditedParentheticals" xlink:type="simple" />
  <link:roleRef roleURI="http://indigoacquisitioncorp.com/20260331/role/CommitmentsandContingenciesDetails" xlink:href="inacu-20260331.xsd#CommitmentsandContingenciesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://indigoacquisitioncorp.com/20260331/role/CondensedStatementsofChangesinShareholdersDeficitUnaudited" xlink:href="inacu-20260331.xsd#CondensedStatementsofChangesinShareholdersDeficitUnaudited" xlink:type="simple" />
  <link:definitionLink xlink:role="http://indigoacquisitioncorp.com/20260331/role/OrganizationandBusinessOperationsDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_EBCMember" xlink:label="inacu_EBCMember_1232" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_IndigoSponsorGroupLLCMember" xlink:label="inacu_IndigoSponsorGroupLLCMember_1812" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_NumberOfUnits" xlink:label="inacu_NumberOfUnits_1240" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_OrganizationandBusinessOperationsDetailsTable" xlink:label="inacu_OrganizationandBusinessOperationsDetailsTable_1219" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_OtherOfferingCosts" xlink:label="inacu_OtherOfferingCosts_1245" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_PercentageOfOutstandingVotingSecurities" xlink:label="inacu_PercentageOfOutstandingVotingSecurities_1247" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_PercentageOfPublicShares" xlink:label="inacu_PercentageOfPublicShares_1248" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_PercentageOfRedeemPublicShares" xlink:label="inacu_PercentageOfRedeemPublicShares_1249" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_PublicShareMember" xlink:label="inacu_PublicShareMember_1225" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_PurchasedAdditionalNumberOfUnits" xlink:label="inacu_PurchasedAdditionalNumberOfUnits_1241" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_SponsorMember" xlink:label="inacu_SponsorMember_1231" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_TransactionCosts" xlink:label="inacu_TransactionCosts_1242" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_UnitsIssuedDuringPeriodSharesNewIssues" xlink:label="inacu_UnitsIssuedDuringPeriodSharesNewIssues_1235" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_WorkingCapitalSurplus" xlink:label="inacu_WorkingCapitalSurplus_1253" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Cash" xlink:label="us-gaap_Cash_1252" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" xlink:label="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_1233" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseOther" xlink:label="us-gaap_InterestExpenseOther_1250" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IPOMember" xlink:label="us-gaap_IPOMember_1222" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NumberOfBusinessesAcquired" xlink:label="us-gaap_NumberOfBusinessesAcquired_1234" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OverAllotmentOptionMember" xlink:label="us-gaap_OverAllotmentOptionMember_1224" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsForUnderwritingExpense" xlink:label="us-gaap_PaymentsForUnderwritingExpense_1243" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PrivatePlacementMember" xlink:label="us-gaap_PrivatePlacementMember_1223" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceInitialPublicOffering" xlink:label="us-gaap_ProceedsFromIssuanceInitialPublicOffering_1237" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceOfPrivatePlacement" xlink:label="us-gaap_ProceedsFromIssuanceOfPrivatePlacement_1239" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain" xlink:label="us-gaap_RelatedPartyDomain_1230" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1229" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_1221" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockPricePerShare" xlink:label="us-gaap_SaleOfStockPricePerShare_1236" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharePrice" xlink:label="us-gaap_SharePrice_1251" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharesIssuedPricePerShare" xlink:label="us-gaap_SharesIssuedPricePerShare_1238" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_1220" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain" xlink:label="dei_EntityDomain_1814" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis" xlink:label="dei_LegalEntityAxis_1813" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_ConditionForFutureBusinessCombinationUseOfProceedsPercentage" xlink:label="inacu_ConditionForFutureBusinessCombinationUseOfProceedsPercentage_1246" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_DeferredUnderwritingFee" xlink:label="inacu_DeferredUnderwritingFee_1244" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_EarlyBirdCapitalIncMember" xlink:label="inacu_EarlyBirdCapitalIncMember_1821" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain" xlink:label="us-gaap_RelatedPartyDomain_1230_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_1221_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain" xlink:label="dei_EntityDomain_1814_default" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain_1230" xlink:to="inacu_EBCMember_1232" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_EntityDomain_1814" xlink:to="inacu_IndigoSponsorGroupLLCMember_1812" />
    <link:definitionArc xlink:type="arc" order="16.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_1233" xlink:to="inacu_NumberOfUnits_1240" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_1233" xlink:to="inacu_OrganizationandBusinessOperationsDetailsTable_1219" />
    <link:definitionArc xlink:type="arc" order="21.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_1233" xlink:to="inacu_OtherOfferingCosts_1245" />
    <link:definitionArc xlink:type="arc" order="23.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_1233" xlink:to="inacu_PercentageOfOutstandingVotingSecurities_1247" />
    <link:definitionArc xlink:type="arc" order="24.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_1233" xlink:to="inacu_PercentageOfPublicShares_1248" />
    <link:definitionArc xlink:type="arc" order="25.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_1233" xlink:to="inacu_PercentageOfRedeemPublicShares_1249" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1221" xlink:to="inacu_PublicShareMember_1225" />
    <link:definitionArc xlink:type="arc" order="17.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_1233" xlink:to="inacu_PurchasedAdditionalNumberOfUnits_1241" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain_1230" xlink:to="inacu_SponsorMember_1231" />
    <link:definitionArc xlink:type="arc" order="18.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_1233" xlink:to="inacu_TransactionCosts_1242" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_1233" xlink:to="inacu_UnitsIssuedDuringPeriodSharesNewIssues_1235" />
    <link:definitionArc xlink:type="arc" order="29.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_1233" xlink:to="inacu_WorkingCapitalSurplus_1253" />
    <link:definitionArc xlink:type="arc" order="28.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_1233" xlink:to="us-gaap_Cash_1252" />
    <link:definitionArc xlink:type="arc" order="26.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_1233" xlink:to="us-gaap_InterestExpenseOther_1250" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1221" xlink:to="us-gaap_IPOMember_1222" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_1233" xlink:to="us-gaap_NumberOfBusinessesAcquired_1234" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1221" xlink:to="us-gaap_OverAllotmentOptionMember_1224" />
    <link:definitionArc xlink:type="arc" order="19.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_1233" xlink:to="us-gaap_PaymentsForUnderwritingExpense_1243" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1221" xlink:to="us-gaap_PrivatePlacementMember_1223" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_1233" xlink:to="us-gaap_ProceedsFromIssuanceInitialPublicOffering_1237" />
    <link:definitionArc xlink:type="arc" order="15.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_1233" xlink:to="us-gaap_ProceedsFromIssuanceOfPrivatePlacement_1239" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1229" xlink:to="us-gaap_RelatedPartyDomain_1230" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="inacu_OrganizationandBusinessOperationsDetailsTable_1219" xlink:to="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1229" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1220" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_1221" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_1233" xlink:to="us-gaap_SaleOfStockPricePerShare_1236" />
    <link:definitionArc xlink:type="arc" order="27.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_1233" xlink:to="us-gaap_SharePrice_1251" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_1233" xlink:to="us-gaap_SharesIssuedPricePerShare_1238" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="inacu_OrganizationandBusinessOperationsDetailsTable_1219" xlink:to="us-gaap_SubsidiarySaleOfStockAxis_1220" />
    <link:definitionArc xlink:type="arc" order="180.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="dei_LegalEntityAxis_1813" xlink:to="dei_EntityDomain_1814" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="inacu_OrganizationandBusinessOperationsDetailsTable_1219" xlink:to="dei_LegalEntityAxis_1813" />
    <link:definitionArc xlink:type="arc" order="22.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_1233" xlink:to="inacu_ConditionForFutureBusinessCombinationUseOfProceedsPercentage_1246" />
    <link:definitionArc xlink:type="arc" order="20.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_1233" xlink:to="inacu_DeferredUnderwritingFee_1244" />
    <link:definitionArc xlink:type="arc" order="187.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_EntityDomain_1814" xlink:to="inacu_EarlyBirdCapitalIncMember_1821" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1229" xlink:to="us-gaap_RelatedPartyDomain_1230_default" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1220" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_1221_default" />
    <link:definitionArc xlink:type="arc" order="180.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="dei_LegalEntityAxis_1813" xlink:to="dei_EntityDomain_1814_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://indigoacquisitioncorp.com/20260331/role/SummaryofSignificantAccountingPoliciesScheduleofBasicandDilutedNetIncomePerOrdinaryShareDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_NonRedeemableOrdinaryShareMember" xlink:label="inacu_NonRedeemableOrdinaryShareMember_1195" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_RedeemableOrdinarySharesMember" xlink:label="inacu_RedeemableOrdinarySharesMember_1194" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_SummaryofSignificantAccountingPoliciesScheduleofBasicandDilutedNetIncomePerOrdinaryShareDetailsLineItems" xlink:label="inacu_SummaryofSignificantAccountingPoliciesScheduleofBasicandDilutedNetIncomePerOrdinaryShareDetailsLineItems_1196" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_SummaryofSignificantAccountingPoliciesScheduleofBasicandDilutedNetIncomePerOrdinaryShareDetailsTable" xlink:label="inacu_SummaryofSignificantAccountingPoliciesScheduleofBasicandDilutedNetIncomePerOrdinaryShareDetailsTable_1192" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1780" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasic" xlink:label="us-gaap_EarningsPerShareBasic_1201" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareDiluted" xlink:label="us-gaap_EarningsPerShareDiluted_1204" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_1198" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasicAbstract" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasicAbstract_1197" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis_1193" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_1203" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_1200" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_1199" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1780_default" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1780" xlink:to="inacu_NonRedeemableOrdinaryShareMember_1195" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1780" xlink:to="inacu_RedeemableOrdinarySharesMember_1194" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="inacu_SummaryofSignificantAccountingPoliciesScheduleofBasicandDilutedNetIncomePerOrdinaryShareDetailsLineItems_1196" xlink:to="inacu_SummaryofSignificantAccountingPoliciesScheduleofBasicandDilutedNetIncomePerOrdinaryShareDetailsTable_1192" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis_1193" xlink:to="us-gaap_ClassOfStockDomain_1780" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_1199" xlink:to="us-gaap_EarningsPerShareBasic_1201" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_1199" xlink:to="us-gaap_EarningsPerShareDiluted_1204" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasicAbstract_1197" xlink:to="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_1198" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="inacu_SummaryofSignificantAccountingPoliciesScheduleofBasicandDilutedNetIncomePerOrdinaryShareDetailsLineItems_1196" xlink:to="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasicAbstract_1197" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="inacu_SummaryofSignificantAccountingPoliciesScheduleofBasicandDilutedNetIncomePerOrdinaryShareDetailsTable_1192" xlink:to="us-gaap_StatementClassOfStockAxis_1193" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_1199" xlink:to="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_1203" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_1199" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_1200" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="inacu_SummaryofSignificantAccountingPoliciesScheduleofBasicandDilutedNetIncomePerOrdinaryShareDetailsLineItems_1196" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_1199" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementClassOfStockAxis_1193" xlink:to="us-gaap_ClassOfStockDomain_1780_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://indigoacquisitioncorp.com/20260331/role/PrivatePlacementsDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1292" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain" xlink:label="us-gaap_RelatedPartyDomain_1293" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_1287" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiarySaleOfStockLineItems" xlink:label="us-gaap_SubsidiarySaleOfStockLineItems_1300" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_1288" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharePrice" xlink:label="us-gaap_SharePrice_1310" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharesIssuedPricePerShare" xlink:label="us-gaap_SharesIssuedPricePerShare_1302" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues_1308" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_BusinessCombinationMember" xlink:label="inacu_BusinessCombinationMember_1820" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_EBCMember" xlink:label="inacu_EBCMember_1295" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_FounderMember" xlink:label="inacu_FounderMember_1296" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_NumberOfPrivateRight" xlink:label="inacu_NumberOfPrivateRight_1306" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_NumberOfPrivateShare" xlink:label="inacu_NumberOfPrivateShare_1305" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_PercentageOfBusinessCombinationOnIpo" xlink:label="inacu_PercentageOfBusinessCombinationOnIpo_1311" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_PercentageOfLikelihoodOfCompletingTheBusinessCombinationAssumed" xlink:label="inacu_PercentageOfLikelihoodOfCompletingTheBusinessCombinationAssumed_1309" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_PrivatePlacementsDetailsTable" xlink:label="inacu_PrivatePlacementsDetailsTable_1286" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_PrivatePlacementUnitsMember" xlink:label="inacu_PrivatePlacementUnitsMember_1290" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_PurchasedAdditionalNumberOfUnits" xlink:label="inacu_PurchasedAdditionalNumberOfUnits_1304" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_SponsorMember" xlink:label="inacu_SponsorMember_1294" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_UnitsIssuedDuringPeriodSharesNewIssues" xlink:label="inacu_UnitsIssuedDuringPeriodSharesNewIssues_1301" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_1819" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="us-gaap_BusinessAcquisitionAxis_1818" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IPOMember" xlink:label="us-gaap_IPOMember_1291" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PrivatePlacementMember" xlink:label="us-gaap_PrivatePlacementMember_1289" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceOfPrivatePlacement" xlink:label="us-gaap_ProceedsFromIssuanceOfPrivatePlacement_1303" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain" xlink:label="us-gaap_RelatedPartyDomain_1293_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_1288_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_1819_default" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="inacu_PrivatePlacementsDetailsTable_1286" xlink:to="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1292" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1292" xlink:to="us-gaap_RelatedPartyDomain_1293" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="inacu_PrivatePlacementsDetailsTable_1286" xlink:to="us-gaap_SubsidiarySaleOfStockAxis_1287" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1287" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_1288" />
    <link:definitionArc xlink:type="arc" order="19.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1300" xlink:to="us-gaap_SharePrice_1310" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1300" xlink:to="us-gaap_SharesIssuedPricePerShare_1302" />
    <link:definitionArc xlink:type="arc" order="17.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1300" xlink:to="us-gaap_StockIssuedDuringPeriodValueNewIssues_1308" />
    <link:definitionArc xlink:type="arc" order="186.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain_1819" xlink:to="inacu_BusinessCombinationMember_1820" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain_1293" xlink:to="inacu_EBCMember_1295" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain_1293" xlink:to="inacu_FounderMember_1296" />
    <link:definitionArc xlink:type="arc" order="15.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1300" xlink:to="inacu_NumberOfPrivateRight_1306" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1300" xlink:to="inacu_NumberOfPrivateShare_1305" />
    <link:definitionArc xlink:type="arc" order="20.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1300" xlink:to="inacu_PercentageOfBusinessCombinationOnIpo_1311" />
    <link:definitionArc xlink:type="arc" order="18.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1300" xlink:to="inacu_PercentageOfLikelihoodOfCompletingTheBusinessCombinationAssumed_1309" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1300" xlink:to="inacu_PrivatePlacementsDetailsTable_1286" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1288" xlink:to="inacu_PrivatePlacementUnitsMember_1290" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1300" xlink:to="inacu_PurchasedAdditionalNumberOfUnits_1304" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain_1293" xlink:to="inacu_SponsorMember_1294" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1300" xlink:to="inacu_UnitsIssuedDuringPeriodSharesNewIssues_1301" />
    <link:definitionArc xlink:type="arc" order="185.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_BusinessAcquisitionAxis_1818" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain_1819" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="inacu_PrivatePlacementsDetailsTable_1286" xlink:to="us-gaap_BusinessAcquisitionAxis_1818" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1288" xlink:to="us-gaap_IPOMember_1291" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1288" xlink:to="us-gaap_PrivatePlacementMember_1289" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems_1300" xlink:to="us-gaap_ProceedsFromIssuanceOfPrivatePlacement_1303" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1292" xlink:to="us-gaap_RelatedPartyDomain_1293_default" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1287" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_1288_default" />
    <link:definitionArc xlink:type="arc" order="185.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_BusinessAcquisitionAxis_1818" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain_1819_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://indigoacquisitioncorp.com/20260331/role/RelatedPartiesDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_RelatedPartyTradingPeriod" xlink:label="inacu_RelatedPartyTradingPeriod_1349" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_SponsorMember" xlink:label="inacu_SponsorMember_1324" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_ThirdPartyMember" xlink:label="inacu_ThirdPartyMember_1327" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_WorkingCapitalLoanMember" xlink:label="inacu_WorkingCapitalLoanMember_1338" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_WorkingCapitalLoans" xlink:label="inacu_WorkingCapitalLoans_1355" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_CounterpartyNameAxis" xlink:label="srt_CounterpartyNameAxis_1318" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_DirectorMember" xlink:label="srt_DirectorMember_1325" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionLineItems" xlink:label="us-gaap_RelatedPartyTransactionLineItems_1339" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1322" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RepaymentsOfRelatedPartyDebt" xlink:label="us-gaap_RepaymentsOfRelatedPartyDebt_1352" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockPricePerShare" xlink:label="us-gaap_SaleOfStockPricePerShare_1347" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharesIssuedPricePerShare" xlink:label="us-gaap_SharesIssuedPricePerShare_1342" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues_1340" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationForfeited" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationForfeited_1343" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_EBCHIndigoLLCMember" xlink:label="inacu_EBCHIndigoLLCMember_1321" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_EBCHoldingsIncMember" xlink:label="inacu_EBCHoldingsIncMember_1320" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_FounderMember" xlink:label="inacu_FounderMember_1326" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_NumberOfSharesRetained" xlink:label="inacu_NumberOfSharesRetained_1344" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues_1341" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NotesPayableOtherPayablesMember" xlink:label="us-gaap_NotesPayableOtherPayablesMember_1334" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsForOtherOperatingActivities" xlink:label="us-gaap_PaymentsForOtherOperatingActivities_1354" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsForRent" xlink:label="us-gaap_PaymentsForRent_1353" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain" xlink:label="us-gaap_RelatedPartyDomain_1323" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RepurchaseAgreementCounterpartyNameDomain" xlink:label="srt_RepurchaseAgreementCounterpartyNameDomain_1319" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConversionOfStockAmountConverted1" xlink:label="us-gaap_ConversionOfStockAmountConverted1_1346" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConversionOfStockSharesConverted1" xlink:label="us-gaap_ConversionOfStockSharesConverted1_1345" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis" xlink:label="us-gaap_DebtInstrumentAxis_1335" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="us-gaap_DebtInstrumentFaceAmount_1350" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="us-gaap_DebtInstrumentNameDomain_1336" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyMember" xlink:label="us-gaap_RelatedPartyMember_1328" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="us-gaap_LongtermDebtTypeAxis_1332" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="us-gaap_LongtermDebtTypeDomain_1333" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NotesPayableCurrent" xlink:label="us-gaap_NotesPayableCurrent_1351" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_PricePerUnit" xlink:label="inacu_PricePerUnit_1356" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_PromissoryNoteMember" xlink:label="inacu_PromissoryNoteMember_1337" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_RelatedPartiesDetailsTable" xlink:label="inacu_RelatedPartiesDetailsTable_1314" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_RelatedPartySharesPercentage" xlink:label="inacu_RelatedPartySharesPercentage_1348" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain" xlink:label="us-gaap_RelatedPartyDomain_1323_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RepurchaseAgreementCounterpartyNameDomain" xlink:label="srt_RepurchaseAgreementCounterpartyNameDomain_1319_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="us-gaap_DebtInstrumentNameDomain_1336_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="us-gaap_LongtermDebtTypeDomain_1333_default" />
    <link:definitionArc xlink:type="arc" order="19.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1339" xlink:to="inacu_RelatedPartyTradingPeriod_1349" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain_1323" xlink:to="inacu_SponsorMember_1324" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain_1323" xlink:to="inacu_ThirdPartyMember_1327" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentNameDomain_1336" xlink:to="inacu_WorkingCapitalLoanMember_1338" />
    <link:definitionArc xlink:type="arc" order="25.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1339" xlink:to="inacu_WorkingCapitalLoans_1355" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="inacu_RelatedPartiesDetailsTable_1314" xlink:to="srt_CounterpartyNameAxis_1318" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain_1323" xlink:to="srt_DirectorMember_1325" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="inacu_RelatedPartiesDetailsTable_1314" xlink:to="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1322" />
    <link:definitionArc xlink:type="arc" order="22.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1339" xlink:to="us-gaap_RepaymentsOfRelatedPartyDebt_1352" />
    <link:definitionArc xlink:type="arc" order="17.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1339" xlink:to="us-gaap_SaleOfStockPricePerShare_1347" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1339" xlink:to="us-gaap_SharesIssuedPricePerShare_1342" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1339" xlink:to="us-gaap_StockIssuedDuringPeriodSharesNewIssues_1340" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1339" xlink:to="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationForfeited_1343" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RepurchaseAgreementCounterpartyNameDomain_1319" xlink:to="inacu_EBCHIndigoLLCMember_1321" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RepurchaseAgreementCounterpartyNameDomain_1319" xlink:to="inacu_EBCHoldingsIncMember_1320" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain_1323" xlink:to="inacu_FounderMember_1326" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1339" xlink:to="inacu_NumberOfSharesRetained_1344" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1339" xlink:to="us-gaap_StockIssuedDuringPeriodValueNewIssues_1341" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LongtermDebtTypeDomain_1333" xlink:to="us-gaap_NotesPayableOtherPayablesMember_1334" />
    <link:definitionArc xlink:type="arc" order="24.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1339" xlink:to="us-gaap_PaymentsForOtherOperatingActivities_1354" />
    <link:definitionArc xlink:type="arc" order="23.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1339" xlink:to="us-gaap_PaymentsForRent_1353" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1322" xlink:to="us-gaap_RelatedPartyDomain_1323" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="srt_CounterpartyNameAxis_1318" xlink:to="srt_RepurchaseAgreementCounterpartyNameDomain_1319" />
    <link:definitionArc xlink:type="arc" order="16.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1339" xlink:to="us-gaap_ConversionOfStockAmountConverted1_1346" />
    <link:definitionArc xlink:type="arc" order="15.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1339" xlink:to="us-gaap_ConversionOfStockSharesConverted1_1345" />
    <link:definitionArc xlink:type="arc" order="16.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="inacu_RelatedPartiesDetailsTable_1314" xlink:to="us-gaap_DebtInstrumentAxis_1335" />
    <link:definitionArc xlink:type="arc" order="20.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1339" xlink:to="us-gaap_DebtInstrumentFaceAmount_1350" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_DebtInstrumentAxis_1335" xlink:to="us-gaap_DebtInstrumentNameDomain_1336" />
    <link:definitionArc xlink:type="arc" order="15.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain_1323" xlink:to="us-gaap_RelatedPartyMember_1328" />
    <link:definitionArc xlink:type="arc" order="15.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="inacu_RelatedPartiesDetailsTable_1314" xlink:to="us-gaap_LongtermDebtTypeAxis_1332" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_LongtermDebtTypeAxis_1332" xlink:to="us-gaap_LongtermDebtTypeDomain_1333" />
    <link:definitionArc xlink:type="arc" order="21.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1339" xlink:to="us-gaap_NotesPayableCurrent_1351" />
    <link:definitionArc xlink:type="arc" order="26.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1339" xlink:to="inacu_PricePerUnit_1356" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentNameDomain_1336" xlink:to="inacu_PromissoryNoteMember_1337" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1339" xlink:to="inacu_RelatedPartiesDetailsTable_1314" />
    <link:definitionArc xlink:type="arc" order="18.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1339" xlink:to="inacu_RelatedPartySharesPercentage_1348" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1322" xlink:to="us-gaap_RelatedPartyDomain_1323_default" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="srt_CounterpartyNameAxis_1318" xlink:to="srt_RepurchaseAgreementCounterpartyNameDomain_1319_default" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_DebtInstrumentAxis_1335" xlink:to="us-gaap_DebtInstrumentNameDomain_1336_default" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_LongtermDebtTypeAxis_1332" xlink:to="us-gaap_LongtermDebtTypeDomain_1333_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://indigoacquisitioncorp.com/20260331/role/Cover" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_AmendmentFlag" xlink:label="dei_AmendmentFlag_1456" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_CityAreaCode" xlink:label="dei_CityAreaCode_1528" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_CurrentFiscalYearEndDate" xlink:label="dei_CurrentFiscalYearEndDate_1488" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentFiscalPeriodFocus" xlink:label="dei_DocumentFiscalPeriodFocus_1463" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentFiscalYearFocus" xlink:label="dei_DocumentFiscalYearFocus_1462" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentInformationLineItems" xlink:label="dei_DocumentInformationLineItems_1410" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentInformationTable" xlink:label="dei_DocumentInformationTable_1407" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentPeriodEndDate" xlink:label="dei_DocumentPeriodEndDate_1461" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentQuarterlyReport" xlink:label="dei_DocumentQuarterlyReport_1421" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentTransitionReport" xlink:label="dei_DocumentTransitionReport_1423" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentType" xlink:label="dei_DocumentType_1411" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressAddressLine1" xlink:label="dei_EntityAddressAddressLine1_1520" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressAddressLine2" xlink:label="dei_EntityAddressAddressLine2_1521" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressCityOrTown" xlink:label="dei_EntityAddressCityOrTown_1522" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressPostalZipCode" xlink:label="dei_EntityAddressPostalZipCode_1525" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressStateOrProvince" xlink:label="dei_EntityAddressStateOrProvince_1523" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCentralIndexKey" xlink:label="dei_EntityCentralIndexKey_1484" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="dei_EntityCommonStockSharesOutstanding_1546" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCurrentReportingStatus" xlink:label="dei_EntityCurrentReportingStatus_1492" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityEmergingGrowthCompany" xlink:label="dei_EntityEmergingGrowthCompany_1498" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityExTransitionPeriod" xlink:label="dei_EntityExTransitionPeriod_1499" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityFileNumber" xlink:label="dei_EntityFileNumber_1496" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityFilerCategory" xlink:label="dei_EntityFilerCategory_1493" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityIncorporationStateCountryCode" xlink:label="dei_EntityIncorporationStateCountryCode_1509" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityInteractiveDataCurrent" xlink:label="dei_EntityInteractiveDataCurrent_1428" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityRegistrantName" xlink:label="dei_EntityRegistrantName_1483" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityShellCompany" xlink:label="dei_EntityShellCompany_1497" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntitySmallBusiness" xlink:label="dei_EntitySmallBusiness_1500" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityTaxIdentificationNumber" xlink:label="dei_EntityTaxIdentificationNumber_1485" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LocalPhoneNumber" xlink:label="dei_LocalPhoneNumber_1529" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_Security12bTitle" xlink:label="dei_Security12bTitle_1547" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_SecurityExchangeName" xlink:label="dei_SecurityExchangeName_1550" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_TradingSymbol" xlink:label="dei_TradingSymbol_1539" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_OrdinarySharesParValuePerShareMember" xlink:label="inacu_OrdinarySharesParValuePerShareMember_1405" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_RightsEachEntitlingHolderToOneTenthOfOneOrdinaryShareUponCompletionOfCompanysInitialBusinessCombinationMember" xlink:label="inacu_RightsEachEntitlingHolderToOneTenthOfOneOrdinaryShareUponCompletionOfCompanysInitialBusinessCombinationMember_1406" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_UnitsEachConsistingOfOneOrdinaryShareAndOneRightMember" xlink:label="inacu_UnitsEachConsistingOfOneOrdinaryShareAndOneRightMember_1404" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1403" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis_1402" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1403_default" />
    <link:definitionArc xlink:type="arc" order="15.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_AmendmentFlag_1456" />
    <link:definitionArc xlink:type="arc" order="31.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_CityAreaCode_1528" />
    <link:definitionArc xlink:type="arc" order="19.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_CurrentFiscalYearEndDate_1488" />
    <link:definitionArc xlink:type="arc" order="17.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_DocumentFiscalPeriodFocus_1463" />
    <link:definitionArc xlink:type="arc" order="18.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_DocumentFiscalYearFocus_1462" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_DocumentInformationTable_1407" />
    <link:definitionArc xlink:type="arc" order="16.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_DocumentPeriodEndDate_1461" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_DocumentQuarterlyReport_1421" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_DocumentTransitionReport_1423" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_DocumentType_1411" />
    <link:definitionArc xlink:type="arc" order="25.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_EntityAddressAddressLine1_1520" />
    <link:definitionArc xlink:type="arc" order="27.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_EntityAddressAddressLine2_1521" />
    <link:definitionArc xlink:type="arc" order="28.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_EntityAddressCityOrTown_1522" />
    <link:definitionArc xlink:type="arc" order="30.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_EntityAddressPostalZipCode_1525" />
    <link:definitionArc xlink:type="arc" order="29.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_EntityAddressStateOrProvince_1523" />
    <link:definitionArc xlink:type="arc" order="21.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_EntityCentralIndexKey_1484" />
    <link:definitionArc xlink:type="arc" order="47.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_EntityCommonStockSharesOutstanding_1546" />
    <link:definitionArc xlink:type="arc" order="34.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_EntityCurrentReportingStatus_1492" />
    <link:definitionArc xlink:type="arc" order="38.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_EntityEmergingGrowthCompany_1498" />
    <link:definitionArc xlink:type="arc" order="39.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_EntityExTransitionPeriod_1499" />
    <link:definitionArc xlink:type="arc" order="22.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_EntityFileNumber_1496" />
    <link:definitionArc xlink:type="arc" order="36.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_EntityFilerCategory_1493" />
    <link:definitionArc xlink:type="arc" order="24.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_EntityIncorporationStateCountryCode_1509" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_EntityInteractiveDataCurrent_1428" />
    <link:definitionArc xlink:type="arc" order="20.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_EntityRegistrantName_1483" />
    <link:definitionArc xlink:type="arc" order="35.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_EntityShellCompany_1497" />
    <link:definitionArc xlink:type="arc" order="37.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_EntitySmallBusiness_1500" />
    <link:definitionArc xlink:type="arc" order="23.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_EntityTaxIdentificationNumber_1485" />
    <link:definitionArc xlink:type="arc" order="26.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_LocalPhoneNumber_1529" />
    <link:definitionArc xlink:type="arc" order="43.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_Security12bTitle_1547" />
    <link:definitionArc xlink:type="arc" order="45.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_SecurityExchangeName_1550" />
    <link:definitionArc xlink:type="arc" order="44.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1410" xlink:to="dei_TradingSymbol_1539" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1403" xlink:to="inacu_OrdinarySharesParValuePerShareMember_1405" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1403" xlink:to="inacu_RightsEachEntitlingHolderToOneTenthOfOneOrdinaryShareUponCompletionOfCompanysInitialBusinessCombinationMember_1406" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1403" xlink:to="inacu_UnitsEachConsistingOfOneOrdinaryShareAndOneRightMember_1404" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis_1402" xlink:to="us-gaap_ClassOfStockDomain_1403" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="dei_DocumentInformationTable_1407" xlink:to="us-gaap_StatementClassOfStockAxis_1402" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementClassOfStockAxis_1402" xlink:to="us-gaap_ClassOfStockDomain_1403_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://indigoacquisitioncorp.com/20260331/role/ShareholdersDeficitDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="us-gaap_CommonStockSharesAuthorized_1386" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesIssued" xlink:label="us-gaap_CommonStockSharesIssued_1389" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_1379" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TemporaryEquitySharesOutstanding" xlink:label="us-gaap_TemporaryEquitySharesOutstanding_1391" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="us-gaap_CommonStockSharesOutstanding_1390" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockVotingRights" xlink:label="us-gaap_CommonStockVotingRights_1388" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain_1377" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IPOMember" xlink:label="us-gaap_IPOMember_1381" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_1380" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SeriesOfIndividuallyImmaterialBusinessAcquisitionsMember" xlink:label="us-gaap_SeriesOfIndividuallyImmaterialBusinessAcquisitionsMember_1384" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis_1376" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_NumberOfOrdinaryShares" xlink:label="inacu_NumberOfOrdinaryShares_1394" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_NumberOfSharesNotForForfeiture" xlink:label="inacu_NumberOfSharesNotForForfeiture_1393" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockLineItems" xlink:label="us-gaap_ClassOfStockLineItems_1385" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember_1378" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare_1387" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_PercentageOfIssuedAndOutstandingOrdinaryShares" xlink:label="inacu_PercentageOfIssuedAndOutstandingOrdinaryShares_1392" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_ShareholdersDeficitDetailsTable" xlink:label="inacu_ShareholdersDeficitDetailsTable_1375" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_1383" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="us-gaap_BusinessAcquisitionAxis_1382" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain_1377_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_1380_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_1383_default" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1385" xlink:to="us-gaap_CommonStockSharesAuthorized_1386" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1385" xlink:to="us-gaap_CommonStockSharesIssued_1389" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="inacu_ShareholdersDeficitDetailsTable_1375" xlink:to="us-gaap_SubsidiarySaleOfStockAxis_1379" />
    <link:definitionArc xlink:type="arc" order="15.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1385" xlink:to="us-gaap_TemporaryEquitySharesOutstanding_1391" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1385" xlink:to="us-gaap_CommonStockSharesOutstanding_1390" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1385" xlink:to="us-gaap_CommonStockVotingRights_1388" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementEquityComponentsAxis_1376" xlink:to="us-gaap_EquityComponentDomain_1377" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1380" xlink:to="us-gaap_IPOMember_1381" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1379" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_1380" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain_1383" xlink:to="us-gaap_SeriesOfIndividuallyImmaterialBusinessAcquisitionsMember_1384" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="inacu_ShareholdersDeficitDetailsTable_1375" xlink:to="us-gaap_StatementEquityComponentsAxis_1376" />
    <link:definitionArc xlink:type="arc" order="18.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1385" xlink:to="inacu_NumberOfOrdinaryShares_1394" />
    <link:definitionArc xlink:type="arc" order="17.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1385" xlink:to="inacu_NumberOfSharesNotForForfeiture_1393" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain_1377" xlink:to="us-gaap_CommonStockMember_1378" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1385" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare_1387" />
    <link:definitionArc xlink:type="arc" order="16.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1385" xlink:to="inacu_PercentageOfIssuedAndOutstandingOrdinaryShares_1392" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_ClassOfStockLineItems_1385" xlink:to="inacu_ShareholdersDeficitDetailsTable_1375" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_BusinessAcquisitionAxis_1382" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain_1383" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="inacu_ShareholdersDeficitDetailsTable_1375" xlink:to="us-gaap_BusinessAcquisitionAxis_1382" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementEquityComponentsAxis_1376" xlink:to="us-gaap_EquityComponentDomain_1377_default" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1379" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_1380_default" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_BusinessAcquisitionAxis_1382" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain_1383_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://indigoacquisitioncorp.com/20260331/role/FairValueMeasurementsScheduleofAssetsthatareMeasuredatFairValueDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsFairValueDisclosureAbstract" xlink:label="us-gaap_AssetsFairValueDisclosureAbstract_1211" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsHeldInTrustNoncurrent" xlink:label="us-gaap_AssetsHeldInTrustNoncurrent_1212" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_1210" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis_1208" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="us-gaap_FairValueInputsLevel1Member_1713" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_1712" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_FairValueMeasurementsScheduleofAssetsthatareMeasuredatFairValueDetailsTable" xlink:label="inacu_FairValueMeasurementsScheduleofAssetsthatareMeasuredatFairValueDetailsTable_1207" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_1712_default" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_1210" xlink:to="us-gaap_AssetsFairValueDisclosureAbstract_1211" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetsFairValueDisclosureAbstract_1211" xlink:to="us-gaap_AssetsHeldInTrustNoncurrent_1212" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="inacu_FairValueMeasurementsScheduleofAssetsthatareMeasuredatFairValueDetailsTable_1207" xlink:to="us-gaap_FairValueByFairValueHierarchyLevelAxis_1208" />
    <link:definitionArc xlink:type="arc" order="92.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_1712" xlink:to="us-gaap_FairValueInputsLevel1Member_1713" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis_1208" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_1712" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_1210" xlink:to="inacu_FairValueMeasurementsScheduleofAssetsthatareMeasuredatFairValueDetailsTable_1207" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="true" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis_1208" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_1712_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://indigoacquisitioncorp.com/20260331/role/CommitmentsandContingenciesDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_CashUnderwritingDiscount" xlink:label="inacu_CashUnderwritingDiscount_1370" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_CashUnderwritingDiscountPerUnit" xlink:label="inacu_CashUnderwritingDiscountPerUnit_1369" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_CommitmentsandContingenciesDetailsTable" xlink:label="inacu_CommitmentsandContingenciesDetailsTable_1359" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_DeferredUnderwritingDiscountPercentage" xlink:label="inacu_DeferredUnderwritingDiscountPercentage_1371" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_1361" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_1360" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TypeOfArrangementAxis" xlink:label="us-gaap_TypeOfArrangementAxis_1363" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember_1364" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingenciesLineItems" xlink:label="us-gaap_LossContingenciesLineItems_1366" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OverAllotmentOptionMember" xlink:label="us-gaap_OverAllotmentOptionMember_1362" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceInitialPublicOffering" xlink:label="us-gaap_ProceedsFromIssuanceInitialPublicOffering_1372" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_UnderwritersOptionPeriodFromDateOfInitialPublicOffering" xlink:label="inacu_UnderwritersOptionPeriodFromDateOfInitialPublicOffering_1367" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_UnderwritingAgreementMember" xlink:label="inacu_UnderwritingAgreementMember_1365" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_UnitsIssuedDuringPeriodSharesNewIssues" xlink:label="inacu_UnitsIssuedDuringPeriodSharesNewIssues_1368" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_1361_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember_1364_default" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LossContingenciesLineItems_1366" xlink:to="inacu_CashUnderwritingDiscount_1370" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LossContingenciesLineItems_1366" xlink:to="inacu_CashUnderwritingDiscountPerUnit_1369" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_LossContingenciesLineItems_1366" xlink:to="inacu_CommitmentsandContingenciesDetailsTable_1359" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LossContingenciesLineItems_1366" xlink:to="inacu_DeferredUnderwritingDiscountPercentage_1371" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1360" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_1361" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="inacu_CommitmentsandContingenciesDetailsTable_1359" xlink:to="us-gaap_SubsidiarySaleOfStockAxis_1360" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="inacu_CommitmentsandContingenciesDetailsTable_1359" xlink:to="us-gaap_TypeOfArrangementAxis_1363" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_TypeOfArrangementAxis_1363" xlink:to="us-gaap_ArrangementsAndNonarrangementTransactionsMember_1364" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1361" xlink:to="us-gaap_OverAllotmentOptionMember_1362" />
    <link:definitionArc xlink:type="arc" order="15.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LossContingenciesLineItems_1366" xlink:to="us-gaap_ProceedsFromIssuanceInitialPublicOffering_1372" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LossContingenciesLineItems_1366" xlink:to="inacu_UnderwritersOptionPeriodFromDateOfInitialPublicOffering_1367" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ArrangementsAndNonarrangementTransactionsMember_1364" xlink:to="inacu_UnderwritingAgreementMember_1365" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LossContingenciesLineItems_1366" xlink:to="inacu_UnitsIssuedDuringPeriodSharesNewIssues_1368" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1360" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_1361_default" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_TypeOfArrangementAxis_1363" xlink:to="us-gaap_ArrangementsAndNonarrangementTransactionsMember_1364_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://indigoacquisitioncorp.com/20260331/role/CondensedStatementsofChangesinShareholdersDeficitUnauditedParentheticals" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable_1716" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationForfeited" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationForfeited_1795" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems_1725" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain" xlink:label="us-gaap_RelatedPartyDomain_1764" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_NumberOfTransferredFounderShares" xlink:label="inacu_NumberOfTransferredFounderShares_1802" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_ThirdPartyMember" xlink:label="inacu_ThirdPartyMember_1765" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_SponsorMember" xlink:label="inacu_SponsorMember_1768" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_CounterpartyNameAxis" xlink:label="srt_CounterpartyNameAxis_1769" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RepurchaseAgreementCounterpartyNameDomain" xlink:label="srt_RepurchaseAgreementCounterpartyNameDomain_1770" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_EBCHIndigoLLCMember" xlink:label="inacu_EBCHIndigoLLCMember_1771" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1763" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain" xlink:label="us-gaap_RelatedPartyDomain_1764_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RepurchaseAgreementCounterpartyNameDomain" xlink:label="srt_RepurchaseAgreementCounterpartyNameDomain_1770_default" />
    <link:definitionArc xlink:type="arc" order="94.00" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_StatementLineItems_1725" xlink:to="us-gaap_StatementTable_1716" />
    <link:definitionArc xlink:type="arc" order="166.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1725" xlink:to="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationForfeited_1795" />
    <link:definitionArc xlink:type="arc" order="141.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1763" xlink:to="us-gaap_RelatedPartyDomain_1764" />
    <link:definitionArc xlink:type="arc" order="170.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1725" xlink:to="inacu_NumberOfTransferredFounderShares_1802" />
    <link:definitionArc xlink:type="arc" order="142.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain_1764" xlink:to="inacu_ThirdPartyMember_1765" />
    <link:definitionArc xlink:type="arc" order="143.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain_1764" xlink:to="inacu_SponsorMember_1768" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_StatementTable_1716" xlink:to="srt_CounterpartyNameAxis_1769" />
    <link:definitionArc xlink:type="arc" order="147.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="srt_CounterpartyNameAxis_1769" xlink:to="srt_RepurchaseAgreementCounterpartyNameDomain_1770" />
    <link:definitionArc xlink:type="arc" order="148.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RepurchaseAgreementCounterpartyNameDomain_1770" xlink:to="inacu_EBCHIndigoLLCMember_1771" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_StatementTable_1716" xlink:to="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1763" />
    <link:definitionArc xlink:type="arc" order="141.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1763" xlink:to="us-gaap_RelatedPartyDomain_1764_default" />
    <link:definitionArc xlink:type="arc" order="147.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="srt_CounterpartyNameAxis_1769" xlink:to="srt_RepurchaseAgreementCounterpartyNameDomain_1770_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://indigoacquisitioncorp.com/20260331/role/CondensedStatementsofOperationsUnaudited" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_NonRedeemableOrdinarySharesMember" xlink:label="inacu_NonRedeemableOrdinarySharesMember_1051" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_OrdinarySharesSubjectToPossibleRedemptionMember" xlink:label="inacu_OrdinarySharesSubjectToPossibleRedemptionMember_1050" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1049" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareDiluted" xlink:label="us-gaap_EarningsPerShareDiluted_1064" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss_1060" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonoperatingIncomeExpense" xlink:label="us-gaap_NonoperatingIncomeExpense_1059" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonoperatingIncomeExpenseAbstract" xlink:label="us-gaap_NonoperatingIncomeExpenseAbstract_1055" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingCostsAndExpenses" xlink:label="us-gaap_OperatingCostsAndExpenses_1053" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss" xlink:label="us-gaap_OperatingIncomeLoss_1054" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensation" xlink:label="us-gaap_ShareBasedCompensation_1057" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis_1048" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems_1052" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable_1047" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_1063" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesIssuedBasic" xlink:label="us-gaap_WeightedAverageNumberOfSharesIssuedBasic_1061" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasic" xlink:label="us-gaap_EarningsPerShareBasic_1062" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIncomeInterestAndDividend" xlink:label="us-gaap_InvestmentIncomeInterestAndDividend_1058" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1049_default" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1049" xlink:to="inacu_NonRedeemableOrdinarySharesMember_1051" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1049" xlink:to="inacu_OrdinarySharesSubjectToPossibleRedemptionMember_1050" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis_1048" xlink:to="us-gaap_ClassOfStockDomain_1049" />
    <link:definitionArc xlink:type="arc" order="18.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1052" xlink:to="us-gaap_EarningsPerShareDiluted_1064" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1052" xlink:to="us-gaap_NetIncomeLoss_1060" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract_1055" xlink:to="us-gaap_NonoperatingIncomeExpense_1059" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1052" xlink:to="us-gaap_NonoperatingIncomeExpenseAbstract_1055" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1052" xlink:to="us-gaap_OperatingCostsAndExpenses_1053" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1052" xlink:to="us-gaap_OperatingIncomeLoss_1054" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract_1055" xlink:to="us-gaap_ShareBasedCompensation_1057" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_StatementTable_1047" xlink:to="us-gaap_StatementClassOfStockAxis_1048" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_StatementLineItems_1052" xlink:to="us-gaap_StatementTable_1047" />
    <link:definitionArc xlink:type="arc" order="17.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1052" xlink:to="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_1063" />
    <link:definitionArc xlink:type="arc" order="15.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1052" xlink:to="us-gaap_WeightedAverageNumberOfSharesIssuedBasic_1061" />
    <link:definitionArc xlink:type="arc" order="16.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1052" xlink:to="us-gaap_EarningsPerShareBasic_1062" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract_1055" xlink:to="us-gaap_InvestmentIncomeInterestAndDividend_1058" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementClassOfStockAxis_1048" xlink:to="us-gaap_ClassOfStockDomain_1049_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://indigoacquisitioncorp.com/20260331/role/InitialPublicOfferingDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_BusinessCombinationMember" xlink:label="inacu_BusinessCombinationMember_1817" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_InitialPublicOfferingDetailsTable" xlink:label="inacu_InitialPublicOfferingDetailsTable_1269" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_NumberOfSharesIssuedPerUnit" xlink:label="inacu_NumberOfSharesIssuedPerUnit_1283" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_NumberOfUnitsSold" xlink:label="inacu_NumberOfUnitsSold_1279" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_PricePerUnit" xlink:label="inacu_PricePerUnit_1280" />
    <link:loc xlink:type="locator" xlink:href="inacu-20260331.xsd#inacu_PublicRightMember" xlink:label="inacu_PublicRightMember_1277" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_1816" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="us-gaap_BusinessAcquisitionAxis_1815" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockLineItems" xlink:label="us-gaap_ClassOfStockLineItems_1278" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember_1272" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain_1271" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IPOMember" xlink:label="us-gaap_IPOMember_1275" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OverAllotmentOptionMember" xlink:label="us-gaap_OverAllotmentOptionMember_1276" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceInitialPublicOffering" xlink:label="us-gaap_ProceedsFromIssuanceInitialPublicOffering_1281" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_1274" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis_1270" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_1273" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_1816_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain_1271_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_1274_default" />
    <link:definitionArc xlink:type="arc" order="183.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain_1816" xlink:to="inacu_BusinessCombinationMember_1817" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_ClassOfStockLineItems_1278" xlink:to="inacu_InitialPublicOfferingDetailsTable_1269" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1278" xlink:to="inacu_NumberOfSharesIssuedPerUnit_1283" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1278" xlink:to="inacu_NumberOfUnitsSold_1279" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1278" xlink:to="inacu_PricePerUnit_1280" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1274" xlink:to="inacu_PublicRightMember_1277" />
    <link:definitionArc xlink:type="arc" order="182.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_BusinessAcquisitionAxis_1815" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain_1816" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="inacu_InitialPublicOfferingDetailsTable_1269" xlink:to="us-gaap_BusinessAcquisitionAxis_1815" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain_1271" xlink:to="us-gaap_CommonStockMember_1272" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementEquityComponentsAxis_1270" xlink:to="us-gaap_EquityComponentDomain_1271" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1274" xlink:to="us-gaap_IPOMember_1275" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1274" xlink:to="us-gaap_OverAllotmentOptionMember_1276" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1278" xlink:to="us-gaap_ProceedsFromIssuanceInitialPublicOffering_1281" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1273" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_1274" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="inacu_InitialPublicOfferingDetailsTable_1269" xlink:to="us-gaap_StatementEquityComponentsAxis_1270" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="inacu_InitialPublicOfferingDetailsTable_1269" xlink:to="us-gaap_SubsidiarySaleOfStockAxis_1273" />
    <link:definitionArc xlink:type="arc" order="182.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_BusinessAcquisitionAxis_1815" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain_1816_default" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementEquityComponentsAxis_1270" xlink:to="us-gaap_EquityComponentDomain_1271_default" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1273" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_1274_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://indigoacquisitioncorp.com/20260331/role/CondensedStatementsofChangesinShareholdersDeficitUnaudited" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="us-gaap_AdditionalPaidInCapitalMember_1070" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition_1803" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember_1069" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain_1072" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss_1087" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity_1088" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TemporaryEquityAccretionToRedemptionValue" xlink:label="us-gaap_TemporaryEquityAccretionToRedemptionValue_1077" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsMember" xlink:label="us-gaap_RetainedEarningsMember_1071" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharesOutstanding" xlink:label="us-gaap_SharesOutstanding_1089" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis_1068" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems_1073" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable_1067" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain_1072_default" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain_1072" xlink:to="us-gaap_AdditionalPaidInCapitalMember_1070" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1073" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition_1803" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain_1072" xlink:to="us-gaap_CommonStockMember_1069" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementEquityComponentsAxis_1068" xlink:to="us-gaap_EquityComponentDomain_1072" />
    <link:definitionArc xlink:type="arc" order="15.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1073" xlink:to="us-gaap_NetIncomeLoss_1087" />
    <link:definitionArc xlink:type="arc" order="16.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1073" xlink:to="us-gaap_StockholdersEquity_1088" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1073" xlink:to="us-gaap_TemporaryEquityAccretionToRedemptionValue_1077" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain_1072" xlink:to="us-gaap_RetainedEarningsMember_1071" />
    <link:definitionArc xlink:type="arc" order="17.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1073" xlink:to="us-gaap_SharesOutstanding_1089" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_StatementTable_1067" xlink:to="us-gaap_StatementEquityComponentsAxis_1068" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_StatementLineItems_1073" xlink:to="us-gaap_StatementTable_1067" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="true" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementEquityComponentsAxis_1068" xlink:to="us-gaap_EquityComponentDomain_1072_default" />
  </link:definitionLink>
  <link:roleRef roleURI="http://fasb.org/srt/role/srt-eedm/ExtensibleEnumerationLists" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-roles-2026.xsd#eedm1" xlink:type="simple" />
  <link:definitionLink xlink:role="http://fasb.org/srt/role/srt-eedm/ExtensibleEnumerationLists" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="srt_TitleOfIndividualWithRelationshipToEntityDomain" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ChiefFinancialOfficerMember" xlink:label="us-gaap_ChiefFinancialOfficerMember" />
    <link:definitionArc xlink:type="arc" order="0" priority="1" xbrldt:closed="true" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:to="us-gaap_ChiefFinancialOfficerMember" />
  </link:definitionLink>
</link:linkbase>
