There are 680 twelve-letter words containing A, E, F and I, https://www.bestwordlist.com/c/a/4/12letterwordswithaefi.htm ACRIFLAVINES AERIFICATION AFFABILITIES AFFECTATIONS AFFECTIONATE AFFECTIONING AFFIRMATIVES AFFLICTIVELY AFFLUENTIALS AFFRANCHISED AFFRANCHISES AFFRICATIVES AFFRIGHTEDLY AFFRIGHTENED AFFRIGHTMENT AFTERBURNING AFTERPARTIES AIRCRAFTSMEN AIRFREIGHTED AMENTIFEROUS ANGLERFISHES ANTIFEBRILES ANTIFEMININE ANTIFEMINISM ANTIFEMINIST AQUAFORTISES ARCHERFISHES ARFVEDSONITE ASSAFOETIDAS ASSUEFACTION BATTLEFIELDS BEATIFICALLY BEAUTIFULLER BENEFACTIONS BENEFICIALLY BENEFICIATED BENEFICIATES BIFLAGELLATE BIOFEEDBACKS BLUESNARFING BREAKFASTING CAFFEINATING CALEFACIENTS CALEFACTIONS CAMPODEIFORM CANDLEFISHES CAULIFLORIES CAULIFLOWERS CEFTRIAXONES CENTRIFUGALS CERTIFICATED CERTIFICATES CHAETIFEROUS CHAUFFEURING CHAUFFEUSING CHIEFTAINESS CLAMJAMFRIES CLASSIFIABLE CLIFFHANGERS COMPACTIFIED COMPACTIFIES CONFERENTIAL CONFESSIONAL CONFIDENTIAL CONFIGURATED CONFIGURATES CONFIRMATIVE CRAFTINESSES CURVIFOLIATE DAFFODILLIES DAMSELFISHES DANDRUFFIEST DEACIDIFYING DECAFFEINATE DECALCIFIERS DECALCIFYING DECLASSIFIED DECLASSIFIES DECRASSIFIED DECRASSIFIES DEFAECATIONS DEFALCATIONS DEFAMATORILY DEFENSATIVES DEFEUDALISED DEFEUDALISES DEFEUDALIZED DEFEUDALIZES DEFIBRILLATE DEFIBRINATED DEFIBRINATES DEFILIATIONS DEFINABILITY DEFINITIONAL DEFLAGRATING DEFLAGRATION DEFLATIONARY DEFLATIONIST DEFLECTIONAL DEFLORATIONS DEFOLIATIONS DEFORCIATION DEFORMALISED DEFORMALISES DEFORMALIZED DEFORMALIZES DEFORMATIONS DEFRAUDATION DEIFICATIONS DESANCTIFIED DESANCTIFIES DIBENZOFURAN DIFFERENTIAE DIFFERENTIAL DIFFRANGIBLE DISAFFECTING DISAFFECTION DISAFFILIATE DISAFFORESTS DISFAVOURERS DISFEATURING DISFRANCHISE DISINFECTANT DISINFESTANT DISQUALIFIED DISQUALIFIER DISQUALIFIES DISREGARDFUL DISSATISFIED DISSATISFIES DOLLARFISHES DRAFTINESSES DRAGONFISHES DWARFISHNESS EDIFICATIONS EFFECTUALITY EFFECTUATING EFFECTUATION EFFEMINACIES EFFEMINATELY EFFEMINATING EFFICACITIES EFFIGURATION EFFLEURAGING EISTEDDFODAU EMULSIFIABLE ENFRANCHISED ENFRANCHISER ENFRANCHISES ENGRAFTATION EXFILTRATING EXFILTRATION EXFOLIATIONS EXSUFFLATING EXSUFFLATION EXSUFFLICATE FABULOSITIES FACEPLANTING FACILENESSES FACILITATIVE FACSIMILEING FACTIONALISE FACTIONALIZE FACTIONARIES FACTIOUSNESS FACTUALITIES FAINEANTISES FAINTHEARTED FAINTISHNESS FAIRNITICKLE FAIRNITICLES FAIRNYTICKLE FAIRNYTICLES FAIRYFLOSSES FAITHFULNESS FALDISTORIES FALLIBLENESS FAMILIARISED FAMILIARISER FAMILIARISES FAMILIARIZED FAMILIARIZER FAMILIARIZES FAMILIARNESS FANCIFULNESS FANTASTICATE FANTASTICOES FARCICALNESS FARNARKELING FARSIGHTEDLY FARTHINGALES FARTHINGLESS FASCICULATED FASCINATEDLY FASCIOLIASES FASHIONABLES FASHIOUSNESS FATHERLINESS FAULTFINDERS FAULTINESSES FEASIBLENESS FEATHERBRAIN FEATHERINESS FEATHERLIGHT FEATLINESSES FEBRIFACIENT FECUNDATIONS FEDERALISING FEDERALISTIC FEDERALIZING FEDERATIVELY FELDSPATHOID FELICITATING FELICITATION FELICITATORS FELSPATHOIDS FEMINALITIES FEMINISATION FEMINIZATION FENESTRATING FENESTRATION FENFLURAMINE FERMENTATION FERMENTATIVE FERRICYANIDE FERRIMAGNETS FERROCYANIDE FERTIGATIONS FERTILISABLE FERTILIZABLE FESTINATIONS FESTIVALGOER FIANCHETTOED FIANCHETTOES FIBERGLASSED FIBERGLASSES FIBERISATION FIBERIZATION FIBREGLASSED FIBREGLASSES FICTIONALISE FICTIONALIZE FIGURATIVELY FILIALNESSES FILLAGREEING FINANCIERING FINASTERIDES FINEABLENESS FINGERBOARDS FINGERGUARDS FINGERPLATES FINGERSTALLS FINICALITIES FIRECRACKERS FIRESCAPINGS FISSICOSTATE FISSIONABLES FISSIPALMATE FLABBINESSES FLABELLATION FLABELLIFORM FLACCIDITIES FLAGELLATING FLAGELLATION FLAGELLIFORM FLAGGINESSES FLAMMIFEROUS FLANNELLIEST FLASHINESSES FLATTERINGLY FLATULENCIES FLAUGHTERING FLAVIVIRUSES FLAVOPROTEIN FLEXITARIANS FLEXOGRAPHIC FLICKERTAILS FLIMFLAMMERS FLIMFLAMMERY FLIPPANTNESS FLUIDEXTRACT FLUORAPATITE FLUPHENAZINE FLUVIOMARINE FLUVOXAMINES FOLLICULATED FOMENTATIONS FONTINALISES FOOLHARDIEST FOOLHARDISES FOOLHARDIZES FOOTWEARIEST FORAMINIFERA FORAMINIFERS FORBEARINGLY FORBIDDANCES FORECARRIAGE FORECASTINGS FOREMANSHIPS FORENSICALLY FOREORDAINED FOREPLANNING FOREREACHING FOREREADINGS FORESLACKING FORESPEAKING FORESTALLING FORESTATIONS FORESTAYSAIL FORESWEARING FORETEACHING FORETRIANGLE FOREWARNINGS FORGATHERING FORGEABILITY FORMALISABLE FORMALIZABLE FORMULARISED FORMULARISER FORMULARISES FORMULARIZED FORMULARIZER FORMULARIZES FORNICATRESS FORTEPIANIST FORWANDERING FOSSILISABLE FOSSILIZABLE FOTHERGILLAS FOUNDATIONER FOUNTAINHEAD FOUNTAINLESS FRACTALITIES FRACTIONATED FRACTIONATES FRACTIONISED FRACTIONISES FRACTIONIZED FRACTIONIZES FRACTIONLETS FRAGMENTISED FRAGMENTISES FRAGMENTIZED FRAGMENTIZES FRANCOPHILES FRANKINCENSE FRANKLINITES FRATCHETIEST FRATERNALISM FRATERNISERS FRATERNISING FRATERNITIES FRATERNIZERS FRATERNIZING FREAKINESSES FREAKISHNESS FREELOADINGS FREESTANDING FRENETICALLY FRESHMANSHIP FRIABILITIES FRICASSEEING FRITILLARIES FRONTALITIES FRONTIERSMAN FRUMENTATION FUNCTIONATED FUNCTIONATES FURAZOLIDONE GEMEINSCHAFT GLANDIFEROUS GODFATHERING GONFALONIERS GRASSFINCHES GUITARFISHES HALFWITTEDLY HALLEFLINTAS HAMFATTERING HANDICRAFTER HANDKERCHIEF HEXAFLUORIDE IDENTIFIABLE IDENTIFIABLY IMPERFORABLE IMPERFORATED INDEFEASIBLE INDEFEASIBLY INDEFINABLES INEFFABILITY INEFFACEABLE INEFFACEABLY INEFFICACIES INEFFICACITY INFAMOUSNESS INFANGTHIEFS INFANTICIDES INFANTILISED INFANTILISES INFANTILIZED INFANTILIZES INFATUATEDLY INFESTATIONS INFEUDATIONS INFILTRATIVE INFLAMMABLES INFLATEDNESS INFLECTIONAL INFLUENTIALS INFOMERCIALS INFORMATISED INFORMATISES INFORMATIZED INFORMATIZES INFORMIDABLE INFOTAINMENT INFRACLASSES INGRAFTMENTS INSUFFERABLE INSUFFERABLY INTERFACINGS INTERFACULTY INTERFEMORAL INTERFLUVIAL INTERFOLIATE INTERFRONTAL INTERGRAFTED INTERTRAFFIC IRREFORMABLE IRREFORMABLY IRREFRAGABLE IRREFRAGABLY LABEFACTIONS LATICIFEROUS LEAPFROGGING LIFEGUARDING LIFEMANSHIPS LIQUEFACIENT LIQUEFACTION LIQUEFACTIVE LIQUIFACTIVE MADEFACTIONS MAGNIFICENCE MALEFACTIONS MALEFICENCES MANIFESTABLE MANIFESTANTS MANIFESTIBLE MANIFESTNESS MANIFESTOING MANIFOLDNESS MEANINGFULLY METAFICTIONS METRIFONATES MICROFINANCE MIDAFTERNOON MISCHANCEFUL MISFEASANCES MISFEATURING MODIFICATIVE MONOFILAMENT MULTIFACETED MULTIFEATURE MULTIFLASHES MULTIFOLIATE MUTESSARIFAT MYOFILAMENTS NEUROFIBROMA NONFACULTIES NONFATTENING OAFISHNESSES OFFICIALESES OFFICIALTIES OUTFANGTHIEF OVERCLASSIFY OVERFAMILIAR OVERFATIGUED OVERFATIGUES OVERFAVORING OVERINFLATED OVERINFLATES OVERSTAFFING PADDLEFISHES PAPULIFEROUS PARAFFINIEST PARFOCALISED PARFOCALISES PARFOCALIZED PARFOCALIZES PARROTFISHES PARVIFOLIATE PERFECTATION PERFOLIATION PERFORATIONS PERFORMATIVE PETALIFEROUS PETRIFACTION PETRIFACTIVE PLACENTIFORM PONTIFICATED PONTIFICATES PREACHIFYING PREAMPLIFIER PREFABRICATE PREFECTORIAL PREFERENTIAL PREFIGURATED PREFIGURATES PREFINANCING PREFLORATION PREFOLIATION PREFORMATION PREFORMATIVE PREQUALIFIED PREQUALIFIES PRIESTCRAFTS PROFESSIONAL PROFESSORIAL PROFESSORIAT PROFLIGACIES PROFLIGATELY PROLIFERATED PROLIFERATES PROOFREADING PUFTALOONIES PURIFICATIVE PUTREFACIENT PUTREFACTION PUTREFACTIVE QUANTIFIABLE QUARTERFINAL RABBITFISHES RANGEFINDERS RANGEFINDING RAREFACTIONS RAREFICATION RECLASSIFIED RECLASSIFIES REFASHIONING REFECTORIANS REFINANCINGS REFLATIONARY REFLECTIONAL REFOCILLATED REFOCILLATES REFORMATIONS REFORMATTING REFOUNDATION REFRACTARIES REFRACTIVELY REFRACTIVITY REFRACTORIES REFRACTORILY REFRACTURING REFRAINMENTS REFRIGERANTS REFRIGERATED REFRIGERATES REFRIGERATOR REFUTABILITY REIFICATIONS REINFLATIONS REQUALIFYING RIBOFLAVINES RIFACIMENTOS RUBEFACIENTS RUBEFACTIONS SACCHARIFIED SACCHARIFIES SAFECRACKING SAFEGUARDING SAFEKEEPINGS SALUTIFEROUS SANCTIFIABLE SANCTIFIEDLY SANGUIFEROUS SAPONIFIABLE SATINFLOWERS SCIENTIFICAL SEMIFINALIST SEMIOFFICIAL SHAPESHIFTER SHEATHFISHES SIGNIFICANCE SIGNIFICATES SIMPLIFIABLE SINFONIETTAS SOLIDIFIABLE SOMNIFACIENT SORBEFACIENT SPACEFARINGS SPACEFLIGHTS SPEARFISHING SPECIFICALLY SPECIFICATED SPECIFICATES SPIFFLICATED SPIFFLICATES STANNIFEROUS STEAMFITTERS STEPFAMILIES STUPEFACIENT STUPEFACTION STUPEFACTIVE SUBFACULTIES SUBFEUDATION SUBINFEUDATE SUFFUMIGATED SUFFUMIGATES SULFADIAZINE SULFADOXINES SULFONAMIDES SUPERFICIALS TABEFACTIONS TEPEFACTIONS TERRAFORMING TERRIFICALLY TESTIFICATES TESTIFICATOR THEREINAFTER THIOSULFATES TIBIOFIBULAE TITANIFEROUS TORREFACTION TRAFFICKIEST TRANSFECTING TRANSFECTION TRANSFERRING TRANSFERRINS TRANSFIGURED TRANSFIGURES TRANSFUSIBLE TRIFOLIOLATE TRYPAFLAVINE TUFTAFFETIES TUMEFACTIONS ULTRAFILTERS ULTRALEFTISM ULTRALEFTIST ULTRAREFINED UNAFFILIATED UNBENEFICIAL UNCLASSIFIED UNCONFINABLE UNDEFOLIATED UNFADINGNESS UNFAIRNESSES UNFATHERLIER UNFEUDALISED UNFEUDALISES UNFEUDALIZED UNFEUDALIZES UNFILTERABLE UNFLATTERING UNFORGIVABLE UNFORMALISED UNFORMALIZED UNFORMIDABLE UNFRANCHISED UNIFOLIOLATE UNMODIFIABLE UNPROFITABLE UNQUANTIFIED UNSANCTIFIED UNSANCTIFIES UNSTRATIFIED UNVERIFIABLE UNVERIFIABLY VERIFICATION VERIFICATIVE VERIFICATORY VERSIFICATOR VITRIFACTURE VOCIFERANCES VOCIFERATING VOCIFERATION VOCIFERATORS WATERFINDERS WATERFOWLING WEARIFULNESS WINEGLASSFUL