There are 415 fifteen-letter words containing A, G, R, S and T, https://www.bestwordlist.com/c/a/5/15letterwordswithagrst.htm ABORIGINALITIES AEROLITHOLOGIES AGGRANDISEMENTS AGGRANDIZEMENTS AGGREGATENESSES AGRANULOCYTOSES AGRANULOCYTOSIS AGRICULTURALIST ALLEGORISATIONS ALLEGORIZATIONS ALLERGENICITIES ANAGRAMMATISING ANGUSTIROSTRATE ANTHROPOGENESES ANTHROPOGENESIS ANTHROPOLOGISTS ANTHROPOPHAGIES ANTHROPOPHAGOUS ANTICARCINOGENS ANTIOESTROGENIC ANTIPROGRESSIVE ANTISEGREGATION APPROXIMEETINGS ARCHEOMAGNETISM ARCHEOZOOLOGIST ARCHGENETHLIACS ARTERIOGRAPHIES ARTIFICIALISING ASTROBIOLOGISTS ASTROGEOLOGISTS ASTRONAVIGATION ASTRONAVIGATORS ASTROPHOTOGRAPH AUTOBIOGRAPHERS AUTOBIOGRAPHIES AUTODESTRUCTING AUTORADIOGRAPHS BACKSCATTERINGS BACKSCRATCHINGS BACTERIOLOGISTS BACTERIOPHAGIES BACTERIOPHAGOUS BIODEGRADATIONS BIOREGIONALISTS BIOSTRATIGRAPHY BLACKGUARDLIEST BREMSSTRAHLUNGS BUREAUCRATISING CARPETBAGGERIES CATEGORICALNESS CATEGORISATIONS CATEGORIZATIONS CATHODOGRAPHERS CATHODOGRAPHIES CENTRIFUGALISED CENTRIFUGALISES CENTRIFUGALIZES CENTRIFUGATIONS CHALCOGRAPHISTS CHARGEABILITIES CHROMATOLOGISTS CIRCUMGYRATIONS CIRCUMNAVIGATES CLIMATOGRAPHIES COADMINISTERING COINVESTIGATORS COLLATERALISING COMMISERATINGLY CONGLOMERATEURS CONGLOMERATIONS CONGRATULATIONS CONNATURALISING CORINTHIANISING COUNTERSHADINGS COUNTERSTAINING COUNTERSTRATEGY CREDENTIALLINGS CROSSOPTERYGIAN CRYPTOGRAPHISTS CRYSTALLOGRAPHY CYBERSQUATTINGS CYTOMEGALOVIRUS DACTYLOGRAPHERS DACTYLOGRAPHIES DAGUERREOTYPERS DAGUERREOTYPIES DAGUERREOTYPIST DEGENERATIONIST DEGLAMORISATION DEGRADABILITIES DEMATERIALISING DEREGISTRATIONS DERMATOGLYPHICS DERMATOGRAPHIAS DERMATOGRAPHIES DIAPHRAGMATITIS DIAPHRAGMITISES DISAGGREGATIONS DISAGREEABILITY DISARRANGEMENTS DISARTICULATING DISCOURAGEMENTS DISHEARTENINGLY DISINTEGRATIONS DISINTHRALLINGS DISINVIGORATING DISNATURALISING DISNATURALIZING DISORGANISATION DISORGANIZATION DOCUMENTARISING DOWNREGULATIONS DRAUGHTSMANSHIP DRAUGHTSPERSONS EARTHSHATTERING EGALITARIANISMS ELECTROGRAPHIES ELECTROMYOGRAMS ELECTROPLATINGS ELECTROSURGICAL EMPYREUMATISING ENTEROGASTRONES EPIGRAMMATISERS EPIGRAMMATISING EPIGRAMMATIZERS ESTRANGEDNESSES EVANGELISTARIES EVANGELISTARION EVERLASTINGNESS EXAGGERATEDNESS EXTRALINGUISTIC FARTHINGSWORTHS FEATHERBEDDINGS FERRIMAGNETISMS FERROMAGNETISMS FIBROCARTILAGES FRACTIONALISING FRAGMENTARINESS GALVANOTROPISMS GASTROENTERITIC GASTROENTERITIS GASTRONOMICALLY GENERALISATIONS GENERALIZATIONS GENTRIFICATIONS GEOMETRISATIONS GEOMETRIZATIONS GEOSTROPHICALLY GERMINABILITIES GEWURZTRAMINERS GINGERBREADIEST GLUTARALDEHYDES GOVERNABILITIES GOVERNMENTALISE GOVERNMENTALISM GOVERNMENTALIST GRAMMATICALNESS GRAMMATICASTERS GRAMMATOLOGISTS GRANGERISATIONS GRANGERIZATIONS GRANULITISATION GRAPHITISATIONS GRAPHITIZATIONS GREISENISATIONS GREISENIZATIONS GUTTURALISATION GYROSTABILISERS GYROSTABILIZERS HIEROGRAMMATIST HISTORIOGRAPHER HISTORIOGRAPHIC HYDROGENISATION IATROGENICITIES IMMATERIALISING INDUSTRIALISING INDUSTRIALIZING INORGANISATIONS INORGANIZATIONS INTEGRABILITIES INTEGRATIONISTS INTERGRADATIONS INTERMIGRATIONS INTEROSCULATING INTERROGATORIES INTRANSIGEANCES INTRANSIGEANTLY INTRANSIGENCIES INTRANSIGENTISM INTRANSIGENTIST IRRATIONALISING KINDERGARTENERS LARYNGECTOMISED LARYNGOSCOPISTS LEGERDEMAINISTS LEGISLATORSHIPS LEXICOGRAPHISTS LIPOGRAMMATISMS LIPOGRAMMATISTS MACROAGGREGATES MACROMARKETINGS MAGISTERIALNESS MAGISTRATESHIPS MAGISTRATICALLY MARGARITIFEROUS MARGINALISATION MEGAVERTEBRATES MELODRAMATISING METAGRABOLISING METAGROBOLISING METALLOGRAPHERS METALLOGRAPHIES METALLOGRAPHIST MICROMARKETINGS MICROPEGMATITES MISAPPRECIATING MISARRANGEMENTS MISARTICULATING MISREGISTRATION MISTRANSCRIBING MONGRELISATIONS MONGRELIZATIONS MOUNTAINEERINGS MULTITHREADINGS NEARSIGHTEDNESS NEUROMARKETINGS NIGHTMARISHNESS NITROGENISATION NONSEGREGATIONS NOTHINGARIANISM OESTROGENICALLY OLIGOMERISATION OPISTHOGRAPHIES ORGANOGRAPHISTS ORGANOMETALLICS ORGANOPHOSPHATE ORGANOTHERAPIES ORTHOGONALISING ORTHOGONALITIES OSMOREGULATIONS OVERADVERTISING OVERDRAMATISING OVEREXAGGERATES OVERMANAGEMENTS OVERREGULATIONS OVERSPECULATING OVERSTIMULATING PALAEOGRAPHISTS PAMPHLETEERINGS PANTOPRAGMATICS PARAGRAMMATISTS PARALINGUISTICS PARASITOLOGICAL PARASITOLOGISTS PARTHENOGENESES PARTHENOGENESIS PARTICULARISING PATRONIZINGNESS PEDESTRIANISING PEDESTRIANIZING PERGAMENTACEOUS PERIGASTRITISES PERINATOLOGISTS PHANTASMAGORIAL PHANTASMAGORIAS PHANTASMAGORIES PHARMACOGNOSIST PHARMACOGNOSTIC PHARMACOLOGISTS PHARYNGOLOGISTS PHOSPHORYLATING PHOTOENGRAVINGS PHOTOTELEGRAPHS PLETHYSMOGRAPHS PLETHYSMOGRAPHY POSTGRADUATIONS POSTHEMORRHAGIC PRAGMATICALNESS PRAGMATISATIONS PRAGMATIZATIONS PREARRANGEMENTS PREDESIGNATIONS PREESTABLISHING PRENEGOTIATIONS PREREGISTRATION PRESTIDIGITATOR PROCRASTINATING PROGNOSTICATING PROGNOSTICATION PROGNOSTICATIVE PROGNOSTICATORS PROPAGABILITIES PSYCHOGERIATRIC PTERYLOGRAPHIES PYRAMIDOLOGISTS PYROPHOTOGRAPHS QUARTERBACKINGS QUINGENTENARIES RADIOAUTOGRAPHS RADIOBIOLOGISTS RADIOTELEGRAPHS RANGATIRATANGAS REACCLIMATISING READMINISTERING RECOGNISABILITY RECONSOLIDATING RECRYSTALLISING RECRYSTALLIZING REDINTEGRATIONS REFRIGERATORIES REGIONALISATION REGULARISATIONS REGULARIZATIONS REHOSPITALISING REHOSPITALIZING REINVESTIGATING REINVESTIGATION REINVIGORATIONS REMATERIALISING REMONSTRATINGLY RENATIONALISING REORCHESTRATING REORGANISATIONS REORGANIZATIONS REREGISTRATIONS RESYSTEMATISING RESYSTEMATIZING RETROGRADATIONS RETROGRESSIONAL RHEUMATOLOGISTS RIGHTABLENESSES RIGIDIFICATIONS ROENTGENISATION ROENTGENOGRAPHS RONTGENISATIONS RONTGENIZATIONS SACERDOTALISING SACERDOTALIZING SAPROGENICITIES SAUROPTERYGIANS SCHOOLMASTERING SCRATCHBUILDING SEGREGATIONISTS SELENOGRAPHISTS SEMILOGARITHMIC SEPTUAGENARIANS SINGULARISATION SINGULARIZATION SLAUGHTERHOUSES SPECTROGRAPHIES SPERMATOGENESES SPERMATOGENESIS SPERMATOGENETIC STALAGMOMETRIES STEGANOGRAPHERS STEGANOGRAPHIES STEGANOGRAPHIST STEREOGRAPHICAL STEREOLOGICALLY STOCKBROKERAGES STRAIGHTFORWARD STRAIGHTJACKETS STRAITJACKETING STRATIGRAPHICAL STRATIGRAPHISTS STRIKEBREAKINGS STRUCTURALISING STRUCTURALIZING SUBAGGREGATIONS SUBCATEGORISING SUBCATEGORIZING SUBCONTRACTINGS SUBORGANISATION SUBORGANIZATION SUPEREROGATIONS SUPERORDINATING SUPERORGANICIST SUPERSATURATING SUSPERCOLLATING SYNERGISTICALLY TELAUTOGRAPHIES TELEPHOTOGRAPHS TERATOGENICISTS TERGIVERSATIONS TETRAGRAMMATONS TETRASPORANGIUM THALASSOGRAPHER THALASSOGRAPHIC THANATOGRAPHIES THEATRICALISING THERMOREGULATES THREMMATOLOGIES TRANQUILISINGLY TRANSFIGURATION TRANSFIGUREMENT TRANSGENDERISMS TRANSGRESSIONAL TRANSGRESSIVELY TRANSISTORISING TRANSISTORIZING TRANSLITERATING TRANSMIGRATIONS TRANSMOGRIFYING TRIANGULARITIES TURBOGENERATORS ULTRASONOGRAPHY UNCATEGORISABLE UNDERESTIMATING UNDERGRADUETTES UNDERSTANDINGLY UNORIGINALITIES UNTRANSMIGRATED UPGRADABILITIES UTEROGESTATIONS ZYGOBRANCHIATES