There are 710 twelve-letter words containing A, 3I and N, https://www.bestwordlist.com/c/a/5/12letterwordswithaiiin.htm
ABIRRITATING ABOLITIONISM ABOLITIONIST ACCIPITRINES ACQUISITIONS
AERIFICATION AEROBICISING AEROBICIZING AFFILIATIONS AGENTIVITIES
ALBUMINISING ALBUMINIZING ALIENABILITY ALKALINISING ALKALINITIES
ALKALINIZING AMOXICILLINS ANISEIKONIAS ANNIHILATING ANNIHILATION
ANNIHILATIVE ANTIADITISES ANTIALIASING ANTICIPATING ANTICIPATION
ANTICIPATIVE ANTICLINORIA ANTIDIABETIC ANTIDILUTION ANTIDIURETIC
ANTIELITISMS ANTIELITISTS ANTIFEMININE ANTIFEMINISM ANTIFEMINIST
ANTIFRICTION ANTIGENICITY ANTIMIGRAINE ANTIMILITARY ANTIMISSILES
ANTIMITOTICS ANTIPERIODIC ANTIPOLITICS ANTIPRURITIC ANTIRACHITIC
ANTIRELIGION ANTITHEISTIC ANTIVITAMINS APPENDICITIS AQUILINITIES
ARTEMISININS ASEPTICISING ASEPTICIZING ASSIBILATING ASSIBILATION
ASSIMILATING ASSIMILATION ASSOILZIEING ATTITUDINISE ATTITUDINIZE
AUDIBILIZING AVITAMINOSIS AVITAMINOTIC AXIOMATISING AXIOMATIZING
BASIFICATION BESTIALISING BESTIALIZING BIBLIOMANIAC BIBLIOMANIAS
BILINGUALISM BILINGUALITY BILLIONAIRES BIMILLENNIAL BIOIDENTICAL
BIOMETRICIAN BIPARTITIONS BIPOLARISING BIPOLARIZING BISOCIATIONS
BITONALITIES BITUMINATING BOUGAINVILIA BRILLIANCIES BRILLIANTINE
BRILLIANTING CALIGINOSITY CANONICITIES CAPITALISING CAPITALIZING
CHARIVARIING CHAUVINISTIC CHRISTIANIAS CINEMATISING CINEMATIZING
CINNARIZINES CITIFICATION CITYFICATION CIVILIANISED CIVILIANISES
CIVILIANIZED CIVILIANIZES CIVILISATION CIVILIZATION CLASSICISING
CLASSICIZING COALITIONISM COALITIONIST CODIFICATION CONCILIATING
CONCILIATION CONCILIATIVE CONVIVIALIST CONVIVIALITY CORDIALISING
CORDIALIZING CRIMINALISED CRIMINALISES CRIMINALISTS CRIMINALIZED
CRIMINALIZES CRIMINATIONS CUTINISATION CUTINIZATION DEACIDIFYING
DEBILITATING DEBILITATION DECIMALISING DECIMALIZING DEFILIATIONS
DEFINABILITY DEFINITIONAL DEIFICATIONS DEIONISATION DEIONIZATION
DELIMITATING DELIMITATION DERIVATISING DERIVATIZING DESALINISING
DESALINIZING DEVIATIONISM DEVIATIONIST DEVITALISING DEVITALIZING
DIALECTICIAN DIATONICISMS DICTIONARIES DIGITALISING DIGITALIZING
DIGITISATION DIGITIZATION DIGLADIATING DIGLADIATION DIJUDICATING
DIJUDICATION DILAPIDATING DILAPIDATION DILUCIDATING DILUCIDATION
DIMERISATION DIMERIZATION DIMIDIATIONS DIMINISHABLE DIPRIONIDIAN
DISAFFIRMING DISAMENITIES DISANIMATING DISANOINTING DISCIPLINANT
DISCIPLINARY DISCRIMINANT DISCRIMINATE DISENTAILING DISIMAGINING
DISINFLATION DISINTRICATE DISSIPATIONS DISSOCIATING DISSOCIATION
DISTILLATION DITRANSITIVE DIVARICATING DIVARICATION DIVINATORIAL
DIVINISATION DIVINIZATION DIVISIONALLY DRINKABILITY EARLIERISING
EARLIERIZING EDIFICATIONS ELASTICISING ELASTICIZING ELICITATIONS
ELIMINATIONS ENIGMATISING ENIGMATIZING ENSILABILITY EOSINOPHILIA
EQUANIMITIES FACILITATING FACILITATION FACSIMILEING FAIRNITICKLE
FAIRNITICLES FANATICISING FANATICIZING FELICITATING FELICITATION
FEMINALITIES FEMINISATION FEMINIZATION FIBERISATION FIBERIZATION
FIBRILLATING FIBRILLATION FICTIONALISE FICTIONALITY FICTIONALIZE
FIMBRIATIONS FINALISATION FINALIZATION FINANCIALIST FINANCIERING
FINICALITIES FISSILINGUAL FLUIDISATION FLUIDIZATION FRANGIBILITY
FUSTIANISING FUSTIANIZING FUSTILIRIANS FUSTILLIRIAN FUTILITARIAN
GAINSTRIVING GAMIFICATION GASIFICATION GELATINISING GELATINIZING
GERIATRICIAN GIGANTICIDES GOLIATHISING GOLIATHIZING GONIATITOIDS
GRAPHITISING GRAPHITIZING GRECIANISING GRECIANIZING HABILITATING
HABILITATION HEPARINISING HEPARINIZING HISPANICISED HISPANICISES
HISPANICISMS HISPANICIZED HISPANICIZES HISPANIOLISE HISPANIOLIZE
HISTRIONICAL HOMINISATION HOMINIZATION HUMIFICATION HUMILIATIONS
IDEALISATION IDEALIZATION IDENTIFIABLE IDENTIFIABLY IDOLATRISING
IDOLATRIZING IDOLISATIONS IDOLIZATIONS IGNITABILITY ILLEGALISING
ILLEGALIZING ILLIMITATION ILLIQUATIONS ILLUMINATING ILLUMINATION
ILLUMINATIVE ILLUVIATIONS IMAGINATIONS IMAGINEERING IMBIBITIONAL
IMBRICATIONS IMMIGRANCIES IMMIGRATIONS IMMISERATING IMMISERATION
IMMUNISATION IMMUNIZATION IMPARADISING IMPASSIONING IMPLICATIONS
INACTIVATING INACTIVATION INACTIVITIES INADMISSIBLE INADMISSIBLY
INANIMATIONS INARTIFICIAL INAUDIBILITY INAUSPICIOUS INCAPABILITY
INCAPACITIES INCENDIARIES INCENDIARISM INCINERATING INCINERATION
INCLINATIONS INCLINATORIA INCOGITATIVE INCRIMINATED INCRIMINATES
INCRIMINATOR INCURABILITY INDELICACIES INDICATIONAL INDICATIVELY
INDIGNATIONS INDIVIDUALLY INDIVIDUATED INDIVIDUATES INDIVIDUATOR
INEBRIATIONS INEFFABILITY INEFFICACIES INEFFICACITY INELASTICITY
INEQUALITIES INERRABILITY INFAMONISING INFAMONIZING INFANTICIDAL
INFANTICIDES INFANTILISED INFANTILISES INFANTILISMS INFANTILIZED
INFANTILIZES INFIBULATING INFIBULATION INFILTRATING INFILTRATION
INFILTRATIVE INFINITATING INFIRMARIANS INFLATIONISM INFLATIONIST
INFURIATIONS INGEMINATING INGEMINATION INGRATIATING INGRATIATION
INHABITATION INHUMANITIES INIMICALNESS INITIALISING INITIALIZING
INITIATIVELY INITIATORIES INITIATRICES INITIATRIXES INJUDICIALLY
INORDINACIES INORDINATION INOSILICATES INQUINATIONS INQUIRATIONS
INSALIVATING INSALIVATION INSANITATION INSECTICIDAL INSEMINATING
INSEMINATION INSINUATIONS INSPIRATIONS INSPISSATING INSPISSATION
INSTIGATIONS INSTILLATION INSULARITIES INSURABILITY INTERDIGITAL
INTERRAILING INTERSTITIAL INTIMIDATING INTIMIDATION INTIMIDATORS
INTIMIDATORY INTOXICATING INTOXICATION INTOXICATIVE INTRANSITIVE
INTRINSICATE INURBANITIES INUSITATIONS INVAGINATING INVAGINATION
INVALIDATING INVALIDATION INVALIDITIES INVARIANCIES INVERACITIES
INVIGILATING INVIGILATION INVIGILATORS INVIGORATING INVIGORATION
INVIGORATIVE INVITATIONAL INVITATORIES IRACUNDITIES IRAIMBILANJA
IRIDISATIONS IRIDIZATIONS IRRADIANCIES IRRADIATIONS IRRADICATING
IRRIGATIONAL IRRITATINGLY ISOANTIGENIC ISOLATIONISM ISOLATIONIST
ITALIANATING ITALIANISING ITALIANIZING ITEMISATIONS ITEMIZATIONS
ITINERANCIES ITINERATIONS KERATINISING KERATINIZING KINESIATRICS
KINESIPATHIC LACINIATIONS LAICISATIONS LAICIZATIONS LAMINARISING
LAMINARIZING LARRIKINISMS LATINISATION LATINIZATION LEGITIMATING
LEGITIMATION LEXICALISING LEXICALIZING LIBERALISING LIBERALIZING
LICENTIATION LILLIPUTIANS LIMINALITIES LIMITATIONAL LINGUISTICAL
LIONISATIONS LIONIZATIONS LIQUIDATIONS LIQUIFACTION LITERALISING
LITERALIZING LIXIVIATIONS LOGISTICIANS MAXIMISATION MAXIMIZATION
MEDICALISING MEDICALIZING MIGRATIONIST MILITARISING MILITARIZING
MILLIONAIRES MILLIONNAIRE MILLIRADIANS MINERALISING MINERALIZING
MINIATURISED MINIATURISES MINIATURISTS MINIATURIZED MINIATURIZES
MINICABBINGS MINIFICATION MINIMALISTIC MINIMISATION MINIMIZATION
MINISTRATION MINISTRATIVE MINORITAIRES MISASSIGNING MISCITATIONS
MISDIAGNOSIS MISSIONARIES MISSIONARISE MISSIONARIZE MOBILISATION
MOBILIZATION MODIFICATION MULTIVITAMIN MUNICIPALISE MUNICIPALISM
MUNICIPALIST MUNICIPALITY MUNICIPALIZE MUSICALISING MUSICALIZING
MUSICIANLIER MUSICIANSHIP NARCISSISTIC NAVIGABILITY NAZIFICATION
NEGATIVISTIC NEGATIVITIES NIACINAMIDES NICOTINAMIDE NICTITATIONS
NIDIFICATING NIDIFICATION NITRANILINES NOBILITATING NOBILITATION
NOMINALISING NOMINALISTIC NOMINALIZING NONIMITATIVE NONINITIATES
NOTABILITIES NOTIFICATION NULLIFIDIANS NUPTIALITIES OFFICIATIONS
OMNIPARITIES OPINIONATING OPINIONATIVE OPTIMALISING OPTIMALIZING
OPTIMISATION OPTIMIZATION ORGANICISTIC ORGANICITIES ORIGINALISMS
ORIGINALISTS ORIGINATIONS OSSIFICATION OXIDISATIONS OXIDIZATIONS
PACIFICATING PACIFICATION PALIFICATION PANIFICATION PARASITISING
PARASITIZING PARTIALISING PARTIALIZING PARTITIONING PARTITIONIST
PATRIALISING PATRIALIZING PEDIATRICIAN PILGRIMAGING PINNATIFIDLY
PINNIPEDIANS PIXILLATIONS PLAGIARISING PLAGIARIZING PLASTICISING
PLASTICIZING PLEINAIRISMS PLEINAIRISTS PRECISIANISM PRECISIANIST
PRINCIPALITY PRINTABILITY PROPITIATING PROPITIATION PURIFICATION
PURITANISING PURITANIZING PYRITHIAMINE QUITCLAIMING RADICALISING
RADICALIZING RADIOIODINES RAMIFICATION RATIFICATION REIFICATIONS
REINHABITING REINITIATING REINITIATION RELATIVISING RELATIVIZING
REVISITATION REVITALISING REVITALIZING SALIFICATION SALINISATION
SALINIZATION SANGUINITIES SANITISATION SANITIZATION SATIRISATION
SATIRIZATION SATISFICINGS SCIENTIFICAL SCINCOIDIANS SEMEIOTICIAN
SEMIFINALIST SEMINALITIES SEMIOTICIANS SHIRTTAILING SIGILLARIANS
SIGILLATIONS SIGNIFICANCE SIGNIFICANCY SIGNIFICANTS SIGNIFICATES
SIGNIFICATOR SILENTIARIES SILLIMANITES SINISTRALITY SITUATIONISM
SMIFLIGATING SOCIALISINGS SOCIALIZINGS SOLICITATION SPANIOLISING
SPANIOLIZING SPATIALISING SPATIALIZING SPECIALISING SPECIALIZING
SPIFLICATING SPIFLICATION STAINABILITY STATISTICIAN STIGMATISING
STIGMATIZING TAILSPINNING TENABILITIES THIORIDAZINE THIOSINAMINE
TITILLATIONS TITTIVATIONS TRADITIONIST TRAINABILITY TRANSITIVITY
TRICHINIASES TRICHINIASIS TRILLIONAIRE TRINITARIANS TRINOMIALISM
TRINOMIALIST TRIPALMITINS TRIPARTITION TRIPLICATING TRIPLICATION
TRIPUDIATING TRIPUDIATION TRIVIALISING TRIVIALIZING TUNABILITIES
TYPIFICATION UBIQUITARIAN UGLIFICATION UMBILICATION UNAMIABILITY
UNARTIFICIAL UNCINARIASIS UNIDEALISTIC UNIFICATIONS UNIONISATION
UNIONIZATION UNITARIANISM UNITISATIONS UNITIZATIONS UTILISATIONS
UTILITARIANS UTILIZATIONS UTOPIANISING UTOPIANIZING VAGINICOLINE
VARIATIONIST VATICINATING VATICINATION VERIFICATION VIGILANTISMS
VILIFICATION VILLAINIZING VILLICATIONS VINDEMIATING VINDICATIONS
VINIFICATION VINIFICATORS VIRGINALISTS VIRGINALLING VIRILISATION
VIRILIZATION VIRTUALISING VIRTUALIZING VISITATIONAL VITALISATION
VITALIZATION VITAMINISING VITAMINIZING VITRIFACTION VITRIOLATING
VITRIOLATION VIVIFICATION VOLATILISING VOLATILIZING ZILLIONAIRES