There are 391 fifteen-letter words containing A, I, N and V, https://www.bestwordlist.com/c/a/4/15letterwordswithainv.htm ACQUISITIVENESS ADDICTIVENESSES ADVERSARINESSES ADVISABLENESSES AFFECTIVENESSES ALTERNATIVENESS ANTICOMPETITIVE ANTICONVULSANTS ANTICONVULSIVES ANTIDERIVATIVES ANTIDEVELOPMENT ANTIPROGRESSIVE ANTIRETROVIRALS ANTISPECULATIVE ANTIVIVISECTION ARGUMENTATIVELY ARIBOFLAVINOSES ARIBOFLAVINOSIS ASSENTIVENESSES ASSERTIVENESSES ASTRONAVIGATION ASTRONAVIGATORS ATTENTIVENESSES ATTRIBUTIVENESS AVAILABLENESSES BIOEQUIVALENCES BOUGAINVILLAEAS CARNIVOROUSNESS CAUSATIVENESSES CIRCUMNAVIGABLE CIRCUMNAVIGATED CIRCUMNAVIGATES CIRCUMNAVIGATOR CIRCUMVALLATING CIRCUMVALLATION CIVILIANISATION CIVILIANIZATION COINVESTIGATORS COMBATIVENESSES COMMUNICATIVELY COMPARATIVENESS CONCEIVABLENESS CONCENTRATIVELY CONSERVATIONIST CONSERVATORIUMS CONSERVATORSHIP CONSIDERATIVELY CONTEMPLATIVELY CONTRACTIVENESS CONTRADICTIVELY CONTRAPOSITIVES CONTRAVALLATION CONTROVERSIALLY CONVALESCENCIES CONVENTIONALISE CONVENTIONALISM CONVENTIONALIST CONVENTIONALITY CONVENTIONALIZE CONVERSATIONISM CONVERSATIONIST CONVEYORISATION CONVEYORIZATION CONVOCATIONISTS CONVULSIONARIES COOPERATIVENESS CORRELATIVENESS COSIGNIFICATIVE COUNTERACTIVELY COUNTERADAPTIVE COUNTERINVASION COUNTERVAILABLE DECONTAMINATIVE DEINDIVIDUATION DEMONSTRATIVELY DERIVATISATIONS DERIVATIZATIONS DESILVERISATION DESILVERIZATION DETERMINATIVELY DEVALORISATIONS DEVALORIZATIONS DEVITALISATIONS DEVITALIZATIONS DEVITRIFICATION DEVOTIONALITIES DIFFRACTIVENESS DISADVANTAGEOUS DISINVIGORATING DISPUTATIVENESS DISSOLVABLENESS DIVERSIFICATION DORSIVENTRALITY DORSOVENTRALITY ELECTRONEGATIVE ENVENOMISATIONS ENVENOMIZATIONS ENVIRONMENTALLY EQUIVOCALNESSES EVANGELICALISMS EVANGELICALNESS EVANGELISATIONS EVANGELISTARIES EVANGELISTARION EVANGELIZATIONS EVERLASTINGNESS EVOCATIVENESSES EXCOMMUNICATIVE EXPANSIVENESSES EXPERIMENTATIVE EXTENSIVISATION EXTENSIVIZATION FLAVOURDYNAMICS FORMATIVENESSES GALVANOMETRICAL GALVANOPLASTIES GALVANOTROPISMS GOVERNABILITIES GOVERNMENTALISE GOVERNMENTALISM GOVERNMENTALIST GOVERNMENTALIZE GRAVIPERCEPTION GRAVITATIONALLY HETERONORMATIVE HYPERSALIVATION HYPERVENTILATED HYPERVENTILATES HYPERVIGILANCES HYPOVENTILATION IMAGINATIVENESS IMITATIVENESSES IMMOVABLENESSES IMPASSIVENESSES IMPERVIABLENESS IMPLICATIVENESS IMPROVISATIONAL INADVISABLENESS INATTENTIVENESS INCENTIVISATION INCENTIVIZATION INCOMMUNICATIVE INDIVIDUALISERS INDIVIDUALISING INDIVIDUALISTIC INDIVIDUALITIES INDIVIDUALIZERS INDIVIDUALIZING INEVITABILITIES INFORMATIVENESS INOPERATIVENESS INSIGNIFICATIVE INSOLVABILITIES INTERACTIVITIES INTERBEHAVIORAL INTERBEHAVIOURS INTERCLAVICULAR INTERDIVISIONAL INTERINDIVIDUAL INTERPROVINCIAL INTERROGATIVELY INTERVALOMETERS INTERVISITATION INTERWEAVEMENTS INTRAVASCULARLY INVARIABILITIES INVESTIGATIONAL INVIOLABILITIES INVIOLATENESSES INVOLUNTARINESS INVULNERABILITY IRREMOVABLENESS IRREVOCABLENESS ITERATIVENESSES LACTOVEGETARIAN LUCRATIVENESSES MACROEVOLUTIONS MANEUVERABILITY MANOEUVRABILITY MISAPPREHENSIVE MISGOVERNAUNCES MISVOCALISATION MISVOCALIZATION MULTIDIVISIONAL MULTIWAVELENGTH NAVIGABLENESSES NEOCONSERVATISM NEOCONSERVATIVE NONACHIEVEMENTS NONADDITIVITIES NONAVAILABILITY NONCONSERVATION NONCONSERVATIVE NONCONVENTIONAL NONCOOPERATIVES NONCREATIVITIES NONCULTIVATIONS NONEQUIVALENCES NONEXPLOITATIVE NONPSYCHOACTIVE NONQUANTITATIVE NONRELATIVISTIC NORMATIVENESSES NOVOCENTENARIES OBSERVATIONALLY OPERATIVENESSES OVERABSTRACTION OVERACHIEVEMENT OVERADVERTISING OVERADVERTIZING OVERAPPLICATION OVERBEARINGNESS OVERCENTRALISED OVERCENTRALISES OVERCENTRALIZED OVERCENTRALIZES OVERCLASSIFYING OVERCOMMUNICATE OVERCOMPLIANCES OVERCULTIVATION OVERDECORATIONS OVERDRAMATISING OVERDRAMATIZING OVERELABORATING OVERELABORATION OVEREMOTIONALLY OVEREMPHASISING OVEREMPHASIZING OVERENCOURAGING OVERENTERTAINED OVERENTHUSIASMS OVERESTIMATIONS OVEREVALUATIONS OVEREXPECTATION OVEREXTRACTIONS OVERGENERALISED OVERGENERALISES OVERGENERALIZED OVERGENERALIZES OVERGLAMORISING OVERGLAMORIZING OVERHASTINESSES OVERIMAGINATIVE OVERMEDICATIONS OVEROPINIONATED OVERORNAMENTING OVERPERSUASIONS OVERPOPULATIONS OVERPREPARATION OVERPROGRAMMING OVERREGULATIONS OVERSATURATIONS OVERSPECULATING OVERSPECULATION OVERSTIMULATING OVERSTIMULATION OVERUTILISATION OVERUTILIZATION PENETRATIVENESS PERVASIVENESSES PHOTOENGRAVINGS PLAINTIVENESSES POSTDEVALUATION POSTVACCINATION PRESERVATIONIST PROCRASTINATIVE PROCREATIVENESS PROGNOSTICATIVE PROVERBIALISING PROVERBIALIZING PROVINCIALISING PROVINCIALITIES PROVINCIALIZING PROVOCATIVENESS QUADRIVALENCIES QUINQUEVALENCES QUINQUIVALENCES RADIOACTIVATING RADIOACTIVATION READVERTISEMENT READVERTIZEMENT REINVESTIGATING REINVESTIGATION REINVIGORATIONS RELATIVISATIONS RELATIVIZATIONS REMONSTRATIVELY REPRESENTATIVES REPRIVATISATION REPRIVATIZATION RESERVATIONISTS RETRIEVABLENESS RETROACTIVENESS REVALORISATIONS REVALORIZATIONS REVEALINGNESSES REVICTIMIZATION REVISUALISATION REVISUALIZATION REVITALISATIONS REVITALIZATIONS REVIVIFICATIONS REVOLUTIONARIES REVOLUTIONARILY SERVICEABLENESS SERVOMECHANICAL SERVOMECHANISMS SIGNIFICATIVELY SPECULATIVENESS SUBCIVILISATION SUBCIVILIZATION SUBSTANTIVENESS SUBSTANTIVISING SUBSTANTIVITIES SUBSTANTIVIZING SUBVERSIONARIES SUBVOCALISATION SUBVOCALIZATION SUPERELEVATIONS SUPERINDIVIDUAL SUPERLATIVENESS SUPEROVULATIONS TALKATIVENESSES TENOVAGINITISES TENTATIVENESSES TERGIVERSATIONS TRANSCRIPTIVELY TRANSGRESSIVELY TRANSVALUATIONS TRANSVESTITISMS TRIVIALISATIONS TRIVIALIZATIONS ULTRACONVENIENT UNADVISABLENESS UNADVISEDNESSES UNAUTHORITATIVE UNAVAILABLENESS UNAVOIDABLENESS UNBELIEVABILITY UNCOMBATIVENESS UNCOMMUNICATIVE UNCONTROVERSIAL UNCONVENTIONALS UNCOOPERATIVELY UNDEMONSTRATIVE UNDERACTIVITIES UNDERVALUATIONS UNEQUIVOCALNESS UNIMAGINATIVELY UNINFORMATIVELY UNIVERSALISABLE UNIVERSALIZABLE UNIVERSALNESSES UNREVOLUTIONARY UNSAVOURINESSES UNVERIFIABILITY VALETUDINARIANS VAPOURISHNESSES VASCULARISATION VASCULARIZATION VASOCONSTRICTOR VASODILATATIONS VENTRILOQUIALLY VERACIOUSNESSES VERITABLENESSES VERNACULARISING VERNACULARITIES VERNACULARIZING VERSATILENESSES VERTICILLATIONS VESTIMENTIFERAN VEXATIOUSNESSES VIBROFLOTATIONS VICARIOUSNESSES VICISSITUDINARY VINDICABILITIES VINDICATIVENESS VIOLINISTICALLY VIRTUALISATIONS VIRTUALIZATIONS VISIONARINESSES VITILITIGATIONS VITRIOLISATIONS VITRIOLIZATIONS VIVACIOUSNESSES VIVISECTIONALLY VOLATILISATIONS VOLATILIZATIONS VOLUNTARINESSES VORACIOUSNESSES VULNERABILITIES