There are 444 thirteen-letter words containing A, M, S, T and U, https://www.bestwordlist.com/c/a/5/13letterwordswithamstu.htm
ACCOUCHEMENTS ACCOUPLEMENTS ACCOUSTREMENT ACCOUTERMENTS ACCOUTREMENTS
ACCUMULATIONS ACCUSTOMATION ACCUSTREMENTS ADMEASUREMENT ADMINICULATES
ADVENTURESOME ALUMINOSITIES AMARANTACEOUS AMBIDEXTEROUS AMBISEXUALITY
AMBITIOUSNESS AMINOTOLUENES AMPHIBLASTULA AMPHIGASTRIUM AMPHITRICHOUS
AMPULLOSITIES ANIMALCULISTS ANNOUNCEMENTS ANTICOMMUNISM ANTICOMMUNIST
ANTIHUMANISMS ANTIHUMANISTS ANTIRITUALISM ANTISMUGGLING ANTISUBMARINE
ASTROTOURISMS AUDIOMETRISTS AUGMENTATIONS AUGMENTATIVES AUTOCHTHONISM
AUTOCOMPLETES AUTOEROTICISM AUTOMOBILISMS AUTOMOBILISTS AUTOMORPHISMS
AUTOSCHEDIASM AUTOTOXAEMIAS AYUNTAMIENTOS BEAUMONTAGUES BEQUEATHMENTS
BICULTURALISM BLABBERMOUTHS BREASTSUMMERS BUREAUCRATISM CALUMNIATIONS
CARCINOMATOUS CATAMOUNTAINS CATECHUMENISM CAUSATIONISMS CENTUMVIRATES
CHEMOAUTROPHS CHONDROMATOUS CHORUSMASTERS CHRYSANTHEMUM CINEMATHEQUES
CIRCUMGYRATES CIRCUMNUTATES CIRCUMROTATES CIRCUMSTANCED CIRCUMSTANCES
CIRCUMSTELLAR CLEISTOGAMOUS COASTGUARDMAN COASTGUARDMEN COLUMNARITIES
COLUMNIATIONS COMMUNALISTIC COMMUNALITIES COMMUNICATEES COMMUNICATORS
COMMUNISATION COMMUNITAIRES COMPURGATIONS CONCEPTUALISM CONDYLOMATOUS
CONSUMMATIONS CONTUMACITIES COSMECEUTICAL COUNTERCHARMS COUNTERCLAIMS
COUNTERIMAGES COUNTERSTREAM CUMULOSTRATUS CUSTOMARINESS CUSTOMISATION
CUSTOMIZATION DARMSTADTIUMS DECUMULATIONS DEMODULATIONS DEMUTUALISING
DESQUAMATIONS DEUTEROGAMIES DEUTEROGAMIST DEUTEROPLASMS DIATHERMANOUS
DISACCUSTOMED DISAMBIGUATED DISAMBIGUATES DISANNULMENTS DISILLUMINATE
DISSIMULATING DISSIMULATION DISSIMULATIVE DISSIMULATORS DOCUMENTALIST
DOCUMENTARIES DOCUMENTARISE DOCUMENTARIST DRAMATURGISTS DRAUGHTSWOMAN
DRAUGHTSWOMEN EMASCULATIONS EMBARQUEMENTS EMPHYSEMATOUS EMPYREUMATISE
ENTOMOPHAGOUS EPITHALAMIUMS EQUESTRIANISM EUDAEMONISTIC EUDAIMONISTIC
EUROTERMINALS EXANTHEMATOUS FLAMMULATIONS FORMULARISTIC FRACTOCUMULUS
FRUITARIANISM FRUMENTACEOUS FRUMENTARIOUS FRUMENTATIONS FUNAMBULATORS
FUNCTIONALISM GASTROCNEMIUS GEITONOGAMOUS GRANULOMATOUS GUESSTIMATING
HAEMATOGENOUS HARMONIUMISTS HELIANTHEMUMS HEMATOPHAGOUS HOMOSEXUALIST
HOMOSEXUALITY HUMANISATIONS HUMANITARIANS HUMANIZATIONS HUMIFICATIONS
HUNTSMANSHIPS HYDROSOMATOUS ILLUMINATIONS IMMUNISATIONS IMMUNIZATIONS
IMMUTABLENESS IMPORTUNACIES IMPOSTHUMATED IMPOSTHUMATES IMPOSTUMATING
IMPOSTUMATION IMPUTABLENESS INDUSTRIALISM INHALATORIUMS INSTRUMENTALS
INTERMUSCULAR INTRAMUSCULAR JUSTICIALISMS KURCHATOVIUMS LANGUISHMENTS
LIGHTHOUSEMAN LUMBERJACKETS MAGISTRATURES MAGNETOPAUSES MAGNITUDINOUS
MALADJUSTMENT MALNUTRITIONS MANIPULATIONS MANIPULATIVES MANSLAUGHTERS
MANUFACTORIES MANUFACTURERS MARICULTURIST MASCULINITIES MASTERFULNESS
MASTURBATIONS MATRICULATORS MEASURABILITY MEDICAMENTOUS MEGASTRUCTURE
MENSTRUATIONS MENSURABILITY MENSURATIONAL MERCURIALISTS METACOMPUTERS
METALANGUAGES METALLIFEROUS METALLURGISTS METHAQUALONES MINIATURISING
MINIATURISTIC MISADJUSTMENT MISADVENTURED MISADVENTURER MISADVENTURES
MISARTICULATE MISASSUMPTION MISATTRIBUTED MISATTRIBUTES MISCALCULATED
MISCALCULATES MISCALCULATOR MISCATALOGUED MISCATALOGUES MISEDUCATIONS
MISEVALUATING MISEVALUATION MISPUNCTUATED MISPUNCTUATES MISQUOTATIONS
MISSUMMATIONS MISUNDERSTAND MITRAILLEUSES MONODACTYLOUS MONOSATURATED
MONOTHALAMOUS MONOTREMATOUS MONUMENTALISE MOUNTAINOUSLY MOUNTAINSIDES
MOUNTEBANKISM MOUNTENAUNCES MOUSETRAPPING MOUSQUETAIRES MUCOCUTANEOUS
MULTIACCESSES MULTIAGENCIES MULTICAMPUSES MULTICHANNELS MULTIFAMILIES
MULTIGRAVIDAS MULTIHOSPITAL MULTIMEGATONS MULTIORGASMIC MULTIPARITIES
MULTIPARTYISM MULTIPLICANDS MULTIPLICATES MULTISPECTRAL MULTISTANDARD
MULTISTRANDED MULTISYLLABIC MULTITASKINGS MULTIVALENCES MULTIVITAMINS
MULTIWARHEADS MULTUNGULATES MUNICIPALISTS MUSCULARITIES MUSICIANLIEST
MUSICOTHERAPY MUTABLENESSES MUTESSARIFATS MUTUALISATION MYCETOPHAGOUS
MYXOEDEMATOUS NEMATODIRUSES NEUROBLASTOMA NOCTAMBULISMS NOCTAMBULISTS
NOMENCLATURES NOMENKLATURAS NONAUTONOMOUS NOUMENALITIES NUMISMATOLOGY
OBSCURANTISMS OMMATOPHOROUS OMNISEXUALITY ORNITHOGALUMS OUTDOORSWOMAN
OUTMANOEUVRES OUTPLACEMENTS OVERAMBITIOUS OVERSTIMULATE PALUDAMENTUMS
PAPILLOMATOUS PARAMENSTRUUM PARAMOUNTCIES PARTICULARISM PERAMBULATORS
PERIOSTRACUMS PERMACULTURES PERPETUALISMS PHARMACEUTICS PHARMACEUTIST
PLAGIOSTOMOUS PNEUMATOLYSES PNEUMATOLYSIS PNEUMOGASTRIC POCOCURANTISM
POLYTHALAMOUS POSTMENOPAUSE POSTMENSTRUAL POSTTRAUMATIC PREFORMULATES
PREMATURENESS PREMATURITIES PROMULGATIONS PROTACTINIUMS PROTANOMALOUS
PRUDENTIALISM PSEUDOMARTYRS PUSILLANIMITY QUARRYMASTERS QUARTERMASTER
RADIOTHORIUMS REACCUSTOMING READJUSTMENTS REASSUMPTIONS REMEASUREMENT
REMUNERATIONS RESTIMULATING RESTIMULATION SANCTIMONIOUS SANSCULOTTISM
SARMENTACEOUS SCAPULIMANTIC SCAPULOMANTIC SCRIPTURALISM SEMIAUTOMATED
SEMIAUTOMATIC SEMIMENSTRUAL SHAMATEURISMS SHOCKUMENTARY SITUATIONISMS
SLUMPFLATIONS SOMATOPLEURAL SOMATOPLEURES SOMATOPLEURIC SOMERSAULTING
SOMNAMBULANTS SOMNAMBULATED SOMNAMBULATES SOMNAMBULATOR SOMNAMBULISTS
SPATHIPHYLLUM SPIRITUALISMS STAMINIFEROUS STIMULATINGLY STRATOCUMULUS
STRUCTURALISM SUBDEPARTMENT SUBMINIATURES SUFFRAGETTISM SUFFUMIGATING
SUFFUMIGATION SULFACETAMIDE SULFONMETHANE SUMMABILITIES SUMMARISATION
SUMMARIZATION SUMMERSAULTED SUPERDIPLOMAT SUPERDOMINANT SUPERHUMANITY
SUPERMAJORITY SUPERMILITANT SUPERROMANTIC SUPERSTARDOMS SUPERSTRATUMS
SUPPLEMENTALS SUPPLEMENTARY SUPRATEMPORAL SURCHARGEMENT SUSTENTACULUM
TAMBOURINISTS TAUROMORPHOUS TAUTOCHRONISM TEMERARIOUSLY TETRADYNAMOUS
THAUMATURGICS THAUMATURGIES THAUMATURGISM THAUMATURGIST TRADUCIANISMS
TRANSEXUALISM TRANSHUMANCES TRANSMOUNTAIN TRANSMUTATION TRANSMUTATIVE
TRANSUMPTIONS TRAUMATONASTY TREPONEMATOUS TRILINGUALISM TRIUMPHALISMS
TRIUMPHALISTS TROUBLEMAKERS TSUTSUGAMUSHI TUMULTUATIONS ULTRALEFTISMS
ULTRALUMINOUS ULTRAMONTANES ULTRAREALISMS ULTRARIGHTISM UMBILICATIONS
UNAMBITIOUSLY UNASSIMILATED UNATHLETICISM UNCHARISMATIC UNCOMPENSATED
UNCOMPLAISANT UNCONSUMMATED UNCUSTOMARILY UNDERESTIMATE UNDERGARMENTS
UNDERLAYMENTS UNDERPAYMENTS UNDERSTRATUMS UNDOMESTICATE UNICAMERALIST
UNILATERALISM UNIMPORTANCES UNITARIANISMS UNMANNERLIEST UNMETABOLISED
UNMINISTERIAL UNMISTAKEABLE UNMISTAKEABLY UNSENTIMENTAL UNSMOTHERABLE
UNSTIGMATISED UNSTIGMATIZED UNSYMMETRICAL UNSYMPATHETIC UNTAMABLENESS
UNTAMEDNESSES UNTRANSFORMED UNTRANSMITTED VANQUISHMENTS VERUMONTANUMS
VOLUNTARYISMS VOUCHSAFEMENT WHATABOUTISMS XERODERMATOUS