There are 420 fifteen-letter words containing A and F, https://www.bestwordlist.com/c/a/2/15letterwordswithaf.htm ABSORBEFACIENTS AFFECTABILITIES AFFECTIVENESSES AFFORDABILITIES AFFRANCHISEMENT AFTERSENSATIONS AFTERTREATMENTS AMMONIFICATIONS ANFRACTUOSITIES ANTIFASHIONABLE ANTIFEDERALISTS ANTIFERROMAGNET ANTIFILIBUSTERS ANTIFORECLOSURE ANTISHOPLIFTING ARIBOFLAVINOSES ARIBOFLAVINOSIS ARTIFICIALISING ARTIFICIALITIES ARTIFICIALIZING AUTOTRANSFORMER AUTOTRANSFUSION BAREFACEDNESSES BEAUTIFICATIONS BEAUTIFULNESSES CALORIFICATIONS CAPRIFOLIACEOUS CENTRIFUGALISED CENTRIFUGALISES CENTRIFUGALIZED CENTRIFUGALIZES CENTRIFUGATIONS CERTIFICATORIES CHANGEFULNESSES CHOLECALCIFEROL CHONDRIFICATION CIRCUMFERENTIAL CIRCUMFORANEOUS CLASSIFICATIONS COCKNEYFICATION COCKNIFICATIONS CODIFIABILITIES COLORFASTNESSES COMFORTABLENESS COMMODIFICATION CONFECTIONARIES CONFESSIONALISM CONFESSIONALIST CONFESSIONARIES CONFIDENTIALITY CONFIGURATIONAL CONFORMABLENESS CONFRATERNITIES CONFRONTATIONAL CONFUSABILITIES CORPORIFICATION COSIGNIFICATIVE COUNTERFACTUALS COUNTERFEISANCE COUNTERFESAUNCE CRESTFALLENNESS DEACIDIFICATION DECALCIFICATION DECERTIFICATION DEDIFFERENTIATE DEFAMILIARIZING DEFEASIBILITIES DEFEMINISATIONS DEFEMINIZATIONS DEFENESTRATIONS DEFIBRILLATIONS DEFLOCCULATIONS DEFORMABILITIES DEFRAGMENTATION DEMOCRATIFIABLE DEMULSIFICATION DEMYSTIFICATION DEMYTHIFICATION DENAZIFICATIONS DENITRIFICATION DENITRIFICATORS DESERTIFICATION DESULFURISATION DESULFURIZATION DETOXIFICATIONS DEVITRIFICATION DEXFENFLURAMINE DIFFERENTIATING DIFFERENTIATION DIFFERENTIATORS DIFFRACTIVENESS DIFFRACTOMETERS DIFFRACTOMETRIC DIFFRANGIBILITY DINOFLAGELLATES DISAFFECTEDNESS DISAFFECTIONATE DISAFFILIATIONS DISAFFIRMATIONS DISAFFORESTMENT DISCONFIRMATION DISENFRANCHISED DISENFRANCHISES DISFEATUREMENTS DISFORESTATIONS DISGRACEFULNESS DISINFESTATIONS DISINFLATIONARY DISINFORMATIONS DISSATISFACTION DISSATISFACTORY DISSYLLABIFYING DISTASTEFULNESS DIVERSIFICATION DRAUGHTPROOFING EBURNIFICATIONS EFFECTUALNESSES EFFICACIOUSNESS ELECTRIFICATION EMULSIFICATIONS ENFRANCHISEMENT ESTERIFICATIONS ETHERIFICATIONS EXEMPLIFICATION EXEMPLIFICATIVE EXTENSIFICATION FACETIOUSNESSES FACTORABILITIES FAITHLESSNESSES FAITHWORTHINESS FAMILIARISATION FAMILIARIZATION FANATICALNESSES FANATICISATIONS FANATICIZATIONS FANTASTICALNESS FANTASTICATIONS FARTHINGSWORTHS FASHIONABLENESS FATHEADEDNESSES FATIGABLENESSES FAULTLESSNESSES FAVORABLENESSES FEATHERBEDDINGS FEATHERSTITCHED FEATHERSTITCHES FEATURELESSNESS FEDERALISATIONS FEDERALIZATIONS FERRIMAGNETISMS FERROMAGNETISMS FERROMANGANESES FERROPRUSSIATES FETISHISTICALLY FIBROCARTILAGES FICTIONISATIONS FICTIONIZATIONS FIDEICOMMISSARY FILTERABILITIES FILTRABLENESSES FISSIPAROUSNESS FLAGELLOMANIACS FLAVOURDYNAMICS FLEXITARIANISMS FLIRTATIOUSNESS FLUOROPHOSPHATE FOOLHARDINESSES FORENSICALITIES FOREORDAINMENTS FOREORDINATIONS FORISFAMILIATED FORISFAMILIATES FORMALISTICALLY FORMATIVENESSES FORMIDABILITIES FORMULARISATION FORMULARIZATION FORTUNATENESSES FRACTIONALISING FRACTIONALIZING FRACTIONISATION FRACTIONIZATION FRACTIOUSNESSES FRAGMENTARINESS FRANGIBLENESSES FRATERNISATIONS FRATERNIZATIONS FRENCHIFICATION FRUCTIFICATIONS FUGACIOUSNESSES FUNCTIONALISTIC FUNCTIONALITIES FUNDAMENTALISMS FUNDAMENTALISTS FUNDAMENTALNESS FUNGISTATICALLY FURACIOUSNESSES FURFURALDEHYDES FUTILITARIANISM GENTRIFICATIONS GRANDFATHERLIER GRANITIFICATION HAEMOFLAGELLATE HALFHEARTEDNESS HALFPENNYWORTHS HEALTHFULNESSES HEMOFLAGELLATES HUMIDIFICATIONS HYPERFASTIDIOUS HYPERFUNCTIONAL HYPERINFLATIONS IDENTIFICATIONS INDEFEASIBILITY INDEFINABLENESS INDEMNIFICATION INEFFABLENESSES INEFFACEABILITY INEFFECTUALNESS INEFFICACIOUSLY INFALLIBILITIES INFANTILISATION INFANTILIZATION INFEASIBILITIES INFINITESIMALLY INFLAMMABLENESS INFORMATIONALLY INFORMATISATION INFORMATIVENESS INFORMATIZATION INFRALAPSARIANS INFRANGIBLENESS INFRASTRUCTURAL INFRASTRUCTURES INSIGNIFICANCES INSIGNIFICANTLY INSIGNIFICATIVE INTENSIFICATION INTERFASCICULAR INTERFRATERNITY INTERSTRATIFIED INTERSTRATIFIES INTRAFASCICULAR IRREFORMABILITY IRREFRAGABILITY IRREFUTABLENESS JUSTIFIABLENESS KAFFEEKLATSCHES KARSTIFICATIONS LACTIFEROUSNESS LAPIDIFICATIONS LATENSIFICATION LIGHTFASTNESSES LIGNOSULFONATES MAGNIFICENTNESS MALCONFORMATION MALFUNCTIONINGS MANIFESTATIONAL MARGARITIFEROUS MASTERFULNESSES MATERFAMILIASES MATRIFOCALITIES METAFICTIONISTS METHOXYFLURANES MICROMICROFARAD MISINFORMATIONS MODIFIABILITIES MULTIFUNCTIONAL NEFARIOUSNESSES NEUROFIBRILLARY NEWFANGLENESSES NONCERTIFICATED NONCONFIDENTIAL NONCONFORMANCES NONFLAMMABILITY NONFUNCTIONALLY NONINFLAMMABLES NONINFLAMMATORY NONINFLATIONARY NONINFLECTIONAL NONINFORMATIONS NONPERFORMANCES NONPROFESSIONAL NONPROFESSORIAL NONQUANTIFIABLE NONSAPONIFIABLE NONSIGNIFICANTS NONSPECIFICALLY NONTRANSFERABLE OBJECTIFICATION OFFHANDEDNESSES OMNIFARIOUSNESS OPSONIFICATIONS OVERCLASSIFYING OVERFAMILIARITY OVERFORWARDNESS PARTURIFACIENTS PASSIFLORACEOUS PATERFAMILIASES PATRIFOCALITIES PERFECTIBILIANS PERFECTIONATING PERFLUOROCARBON PERSONIFICATION PHOTOFLUOROGRAM PHOTOREFRACTIVE PHYTOFLAGELLATE PONTIFICALITIES POSTTRANSFUSION PRAYERFULNESSES PREFABRICATIONS PREFERABILITIES PREFERENTIALISM PREFERENTIALIST PREFERENTIALITY PREFIGURATIVELY PREFORMATIONISM PREFORMATIONIST PREMANUFACTURED PREMANUFACTURES PREMODIFICATION PRENOTIFICATION PREPERFORMANCES PREPROFESSIONAL PRETTIFICATIONS PROFESSIONALISE PROFESSIONALISM PROFESSIONALIST PROFESSIONALIZE PROFITABILITIES QUANTIFICATIONS QUARTERFINALIST QUIZZIFICATIONS REAFFORESTATION RECERTIFICATION RECODIFICATIONS RECONFIGURATION RECONFIRMATIONS REFORMABILITIES REFORMATIONISTS REFORTIFICATION REFRACTOMETRIES REFRANGIBLENESS REFRIGERATORIES REFUNDABILITIES REGARDFULNESSES REMANUFACTURERS REMANUFACTURING REPROACHFULNESS RESINIFICATIONS REVIVIFICATIONS RIGIDIFICATIONS SANCTIFICATIONS SANGUIFICATIONS SAPONIFICATIONS SCATHEFULNESSES SCHIZOAFFECTIVE SEMIMANUFACTURE SHAMEFASTNESSES SIGNIFICATIVELY SILICIFICATIONS SIMPLIFICATIONS SLUMPFLATIONARY SOFTHEARTEDNESS SOLEMNIFICATION SOLIDIFICATIONS SOOTHFASTNESSES SPEECHIFICATION STANDOFFISHNESS STEADFASTNESSES STRAIGHTFORWARD STRATIFICATIONS STULTIFICATIONS SUBINFEUDATIONS SUBPROFESSIONAL SUBSPECIFICALLY SULFAMETHAZINES SULFINPYRAZONES SUPERFICIALISED SUPERFICIALISES SUPERFICIALIZED SUPERFICIALIZES SUPERFICIALNESS SUPERFOETATIONS SYLLABIFICATION TENTACULIFEROUS TETRAHYDROFURAN TRANSFERABILITY TRANSFIGURATION TRANSFIGUREMENT TRANSFORMATIONS TRANSFUSIONISTS TRANSMOGRIFYING TRIFLUOPERAZINE ULTRACENTRIFUGE ULTRAFASTIDIOUS ULTRAFILTRATION UNDERINFLATIONS UNFAILINGNESSES UNFAMILIARITIES UNFAVORABLENESS UNFLAPPABLENESS UNFORTUNATENESS UNHEALTHFULNESS UNIFORMITARIANS UNINFORMATIVELY UNPROFESSIONALS UNPROFITABILITY UNQUALIFIEDNESS UNSATISFACTIONS UNSATISFIEDNESS UNSTEADFASTNESS UNTACTFULNESSES UNTRANSFERRABLE UNVERIFIABILITY VERIFIABILITIES VESTIMENTIFERAN VIBROFLOTATIONS WASTERFULNESSES WEATHERPROOFING ZINCKIFICATIONS