There are 648 thirteen-letter words containing A, C, E, M and S, https://www.bestwordlist.com/c/a/5/13letterwordswithacems.htm ACADEMICALISM ACATAMATHESIA ACCIDENTALISM ACCLIMATISERS ACCLIMATIZERS ACCOMPLISHERS ACCOUCHEMENTS ACCOUPLEMENTS ACCOUSTREMENT ACCOUTERMENTS ACCOUTREMENTS ACCUSTREMENTS ACTINOMETRIES ACTINOMYCETES ACTINOMYCOSES ADMINICULATES ADRENOCHROMES AEROMECHANICS AEROMEDICINES AESTHETICISMS AGRICHEMICALS AGROCHEMICALS ALCHEMISTICAL ALEMBICATIONS ALEXIPHARMICS ALPHANUMERICS AMARANTACEOUS AMBIVALENCIES AMICABILITIES AMNIOCENTESES AMNIOCENTESIS AMPHICTYONIES AMYGDALACEOUS ANDROCENTRISM ANDRODIOECISM ANECDOTALISMS ANISOMETROPIC ANNOUNCEMENTS ANTHELMINTICS ANTIMECHANIST ANTIMNEMONICS ANTISEPTICISM ANTISYMMETRIC ARCHEOMETRIES ARCHIPHONEMES AROMATICITIES ARTHRECTOMIES ASCERTAINMENT ASSEMBLAUNCES ASTROMETRICAL ATMOSPHERICAL AUTOCOMPLETES AUTOEROTICISM AUTOSCHEDIASM BACKSWORDSMEN BASIDIOMYCETE BEACHCOMBINGS BENCHMARKINGS BIBLIOMANCIES BICAMERALISMS BICAMERALISTS BIMETALLISTIC BIOMETRICIANS BIOSYSTEMATIC BISYMMETRICAL BLASTOMYCOSES BOTANOMANCIES BRACHYPTERISM BROMELIACEOUS BUREAUCRATISM CABINETMAKERS CACKERMANDERS CAESAROPAPISM CALORIMETRIES CAMERAPERSONS CAMPANOLOGERS CAMPANOLOGIES CAMPHORACEOUS CAPELLMEISTER CARPETMONGERS CATECHUMENISM CATHETOMETERS CATHIODERMIES CENTUMVIRATES CEPHALOMETERS CEPHALOTOMIES CEREMONIALISM CEREMONIALIST CERULOPLASMIN CHAENOMELESES CHALAZOGAMIES CHAMPIONESSES CHARACTERISMS CHASTISEMENTS CHEIROMANCERS CHEIROMANCIES CHEMOAUTROPHS CHEMOSURGICAL CHIMNEYBOARDS CHIMNEYBREAST CHLAMYDOSPORE CHLORENCHYMAS CHONDROSAMINE CHORUSMASTERS CHREMATISTICS CHRESTOMATHIC CHRISMATORIES CHROMATICNESS CHROMATOLYSES CHRYSANTHEMUM CINEMATHEQUES CIRCUMAMBAGES CIRCUMGYRATES CIRCUMNUTATES CIRCUMROTATES CIRCUMSTANCED CIRCUMSTANCES CIRCUMSTELLAR CLAMJAMPHRIES CLAMOROUSNESS CLAVICEMBALOS CLEISTOGAMIES CLEISTOGAMOUS CLEPTOMANIACS CLIMATOLOGIES CLISHMACLAVER CLOMIPRAMINES CLOTRIMAZOLES COADMINISTERS COASTGUARDMEN COLLEGIALISMS COLUMNARITIES COMANAGEMENTS COMBATIVENESS COMICALNESSES COMMANDERSHIP COMMEASURABLE COMMEMORATORS COMMENDATIONS COMMENSALISMS COMMENSURABLE COMMENSURABLY COMMENTARIATS COMMENTATIONS COMMERCIALESE COMMERCIALISE COMMERCIALISM COMMERCIALIST COMMISERATING COMMISERATION COMMISERATIVE COMMISERATORS COMMONALITIES COMMONWEALTHS COMMUNALISERS COMMUNALITIES COMMUNALIZERS COMMUNICATEES COMMUNITAIRES COMPACTEDNESS COMPACTNESSES COMPANIONLESS COMPASSIONATE COMPELLATIONS COMPELLATIVES COMPENSATIONS COMPLACENCIES COMPLAISANCES COMPLEXATIONS COMPLIANTNESS COMPRESSIONAL COMRADELINESS CONCEPTUALISM CONCERTMASTER CONCOMITANCES CONCREMATIONS CONDEMNATIONS CONGLOMERATES CONGRESSWOMAN CONSERVATISMS CONTEMPLATIST CONTEMPLATORS CONTUMACITIES CORPOREALISMS COSMECEUTICAL COSMOCHEMICAL COSMOGRAPHERS COSMOGRAPHIES COSMOTHETICAL COSTARDMONGER COUNTERCHARMS COUNTERCLAIMS COUNTERIMAGES COUNTERSTREAM CRAFTSMANLIKE CRANIECTOMIES CRANIOGNOMIES CRANIOMETRIES CRANIOMETRIST CREDENTIALISM CREMATIONISMS CREMATIONISTS CRIMINALITIES CRITHOMANCIES CRYPTOMNESIAS CUSTOMARINESS CYTOMEMBRANES DECALCOMANIAS DECOMPENSATED DECOMPENSATES DECRIMINALISE DECUMULATIONS DEMOCRATISERS DEMOCRATISING DEMOCRATIZERS DEMONOCRACIES DETERMINACIES DIALECTICISMS DIATHERMACIES DIATOMICITIES DICHLAMYDEOUS DISACCUSTOMED DISAFFIRMANCE DISCOMEDUSANS DISCRIMINABLE DISCRIMINATED DISCRIMINATES DISPLACEMENTS DISSEMBLANCES DOCUMENTALIST DOCUMENTARIES DOCUMENTARISE DOCUMENTARIST DODECAPHONISM DOMESTICATING DOMESTICATION DOMESTICATIVE DOMESTICATORS DOSIMETRICIAN ECCREMOCARPUS ECONOMISATION ECOTARIANISMS ECUMENICALISM ELASMOBRANCHS EMANCIPATIONS EMASCULATIONS EMBRACINGNESS EMBRANCHMENTS EMPIRICALNESS ENCOMIASTICAL ENCOMPASSMENT ENCROACHMENTS ENCUMBRANCERS ENTOMOSTRACAN ENTRANCEMENTS EPICUREANISMS EPISCOPALISMS EPISTEMICALLY ETHEROMANIACS EUDAEMONISTIC EUDAIMONISTIC EVANGELICISMS FIDEICOMMISSA FLAMBOYANCIES FRANCHISEMENT FRUMENTACEOUS GALACTOMETERS GALACTOSAEMIA GALACTOSAEMIC GALACTOSAMINE GALACTOSEMIAS GASTRECTOMIES GASTROCNEMIUS GASTROMANCIES GEMEINSCHAFTS GEODYNAMICIST GEOMETRICIANS GIMCRACKERIES GONADECTOMIES GRAMMATICISED GRAMMATICISES GRAMMATICIZES GREENBACKISMS GYNAECOMASTIA GYNECOMASTIAS GYROCOMPASSES HAEMODYNAMICS HAEMOPHILIACS HANDCRAFTSMEN HEMATOBLASTIC HEMICHORDATES HEMIPARASITIC HEMISPHERICAL HEPATECTOMIES HISTAMINERGIC HISTOCHEMICAL HOCHMAGANDIES HOMOSCEDASTIC HYPERSARCOMAS HYPOCALCEMIAS HYPOGLYCEMIAS HYPSOMETRICAL IATROCHEMISTS IDIOMATICNESS IMMANENTISTIC IMMARCESCIBLE IMPERIALISTIC IMPERMANENCES IMPORTUNACIES INCENDIARISMS INCOMPATIBLES INCOMPLIANCES INCUMBRANCERS INDOMETHACINS INIMICALITIES INTEMPERANCES INTERCOMPARES INTERMUSCULAR ISMATICALNESS ISOBAROMETRIC ISOCHEIMENALS ISOMETRICALLY KERATECTOMIES KLEPTOMANIACS LAMINECTOMIES LOWERCLASSMAN LOWERCLASSMEN LUMBERJACKETS LUMBRICALISES MACHIAVELIANS MACROCLIMATES MAGNETOSTATIC MAGNIFICENCES MAGNOLIACEOUS MAJOLICAWARES MALACOPHILIES MALICIOUSNESS MANNERISTICAL MANUFACTORIES MANUFACTURERS MARCHIONESSES MASCULINENESS MASCULINITIES MASTERCLASSES MASTICATORIES MASTOIDECTOMY MATCHLESSNESS MATERIALISTIC MATERNALISTIC MATHEMATICISE MATHEMATICISM MATRIARCHATES MECAMYLAMINES MECHANICALISM MECHANISATION MEDICAMENTOUS MEDIEVALISTIC MEGACEPHALIES MEGACEPHALOUS MEGALOBLASTIC MEGALOCARDIAS MEGALOMANIACS MEGASTRUCTURE MELANCHOLIACS MELANCHOLIOUS MELANOCHROOUS MELODRAMATICS MEMBRANACEOUS MERCANTILISMS MERCANTILISTS MERCENARINESS MERCERISATION MERCHANDISERS MERCHANDISING MERCHANDIZERS MERCURIALISED MERCURIALISES MERCURIALISMS MERCURIALISTS MERCURIALIZES MERCURIALNESS MERITOCRACIES MESATICEPHALY MESENCEPHALIC MESENCEPHALON MESOCEPHALICS MESOCEPHALIES MESOCEPHALISM MESOCEPHALOUS MESSIANICALLY METACERCARIAS METACHRONISMS METACOMPUTERS METAPHYSICIAN METAPHYSICISE METAPHYSICIST METAPHYSICIZE METAPSYCHICAL METASILICATES METHACRYLATES MICROANALYSES MICROBALANCES MICROCAPSULES MICROCASSETTE MICROCLIMATES MICROFINANCES MICROGRANITES MICROGRAPHERS MICROGRAPHIES MICROMACHINES MICROMANAGERS MICROPARASITE MICROPAYMENTS MINICASSETTES MISADVERTENCE MISAPPRECIATE MISARTICULATE MISCALCULATED MISCALCULATES MISCATALOGUED MISCATALOGUES MISCEGENATING MISCEGENATION MISCEGENATORS MISCELLANEOUS MISCELLANISTS MISCHALLENGES MISCHANNELING MISCHANNELLED MISCLASSIFIED MISCLASSIFIES MISEDUCATIONS MISGOVERNANCE MISMATCHMENTS MISOBSERVANCE MISPLACEMENTS MISPUNCTUATED MISPUNCTUATES MISTRANSCRIBE MONEYCHANGERS MONOCHROMATES MONOVALENCIES MOUNTENAUNCES MUCKSPREADERS MUCKSPREADING MUCOCUTANEOUS MULTIACCESSES MULTIAGENCIES MULTICAMPUSES MULTICHANNELS MULTIPLICATES MULTISPECTRAL MULTIVALENCES MUNICIPALISED MUNICIPALISES MUNICIPALIZES MUSCULARITIES MUSICALNESSES MUSICIANLIEST MUSICOTHERAPY MUSSELCRACKER MYCETOPHAGOUS MYCOPLASMOSES MYOCARDITISES NANOCOMPOSITE NEOCAPITALISM NEOCLASSICISM NEOPLASTICISM NEUROMUSCULAR NICOTINAMIDES NOMENCLATURES NONSYSTEMATIC NUCLEOPLASMIC NYMPHAEACEOUS OCCIDENTALISM OLEANDOMYCINS OLFACTOMETERS ONEIROMANCERS ONEIROMANCIES ONYCHOMANCIES OSTEOMALACIAL OSTEOMALACIAS OSTEOSARCOMAS OUTPLACEMENTS OVARIECTOMIES OVERCRAMMINGS OVERDRAMATICS OVERMEDICATES PANCREOZYMINS PARAMOUNTCIES PARARESCUEMAN PARARESCUEMEN PARCHMENTIEST PARCHMENTISED PARCHMENTISES PARCHMENTIZES PERIOSTRACUMS PERMACULTURES PESSIMISTICAL PHARMACEUTICS PHARMACEUTIST PHARMACOPEIAS PHLEGMAGOGICS PHOTOMACHINES PICROCARMINES PNEUMOGASTRIC POLYCYTHEMIAS POSTVASECTOMY PRECISIANISMS PREDOMINANCES PREECLAMPSIAS PROSENCHYMATA PROSTATECTOMY PSYCHOMACHIES RACEMISATIONS RACEMIZATIONS RADIOCHEMISTS REACCLIMATISE REACCUSTOMING REACTIONARISM READMITTANCES REATTACHMENTS RECOMPENSABLE RECRIMINATORS REFLECTOGRAMS REMEMBRANCERS REMONSTRANCES REPUBLICANISM RHABDOMANCERS RHABDOMANCIES RHINOSCLEROMA SACCHARIMETER SACCHARIMETRY SACCHAROMETER SACCHAROMETRY SACCHAROMYCES SACERDOTALISM SACRAMENTALLY SALICYLAMIDES SALPINGECTOMY SARMENTACEOUS SCALPELLIFORM SCANDALMONGER SCAPEGOATISMS SCATTEROMETER SCHEMATICALLY SCHLUMBERGERA SCHOOLMASTERS SCHWARMERISCH SCLERENCHYMAS SCLERODERMATA SCLERODERMIAS SCLEROMALACIA SCRIMSHANDERS SCRIMSHANDIED SCRIMSHANDIES SCRIMSHANKERS SECTARIANISMS SECTIONALISMS SEISMOGRAPHIC SEISMOLOGICAL SEMEIOLOGICAL SEMEIOTICALLY SEMEIOTICIANS SEMIABSTRACTS SEMIAUTOMATIC SEMICARBAZIDE SEMICARBAZONE SEMICLASSICAL SEMICONSONANT SEMIDETACHEDS SEMIEMPIRICAL SEMIOCHEMICAL SEMIOFFICIALS SEMIPARASITIC SEMIPOLITICAL SEMIPORCELAIN SEMITONICALLY SHOCKUMENTARY SIMARUBACEOUS SOMATOPLEURIC SOMNAMBULANCE SOMNIFACIENTS SPEECHMAKINGS SPERMATICALLY SPERMATOCELES SPERMATOCIDAL SPERMATOCIDES SPERMATOCYTES SPERMATOGENIC SPERMATOTHECA STAGECOACHMAN STAGECOACHMEN STERCORANISMS SULFACETAMIDE SUPERCOLUMNAR SUPERCRIMINAL SUPERROMANTIC SUPRAMOLECULE SURCHARGEMENT SUSTENTACULUM SYMMETRICALLY SYMPATHECTOMY SYMPATHETICAL SYNAPOSEMATIC SYSTEMATICIAN TACHEOMETRIES TECHNOMANIACS TELEFACSIMILE TEPHROMANCIES TETRADRACHMAS THALASSAEMICS THEATRICALISM THERMOPLASTIC THERMOSTATICS THORACOTOMIES TRACHEOTOMIES TRAGICOMEDIES TRANSCRIPTOME TRANSHUMANCES TRANSMITTANCE TRICHOMONASES TROCHEAMETERS UNATHLETICISM UNCOMPENSATED UNCONSUMMATED UNDERCLASSMAN UNDERCLASSMEN UNDOMESTICATE UNICAMERALISM UNICAMERALIST UNIMPORTANCES UNMACADAMISED UNMECHANISING UNMUSICALNESS UNSYMMETRICAL UNSYMPATHETIC UPPERCLASSMAN UPPERCLASSMEN VAGINECTOMIES VASECTOMISING VASECTOMIZING VERNACULARISM VISCOMETRICAL VOUCHSAFEMENT VRAISEMBLANCE WHIMSICALNESS WOODCRAFTSMEN