There are 501 thirteen-letter words containing 3A, https://www.bestwordlist.com/c/a/3/13letterwordswithaaa.htm
ABSQUATULATED ABSQUATULATES ABSTRACTIONAL ACADEMICALISM ACARIDOMATIUM
ACARODOMATIUM ACATAMATHESIA ACCIACCATURAS ACCLIMATATION ACETAZOLAMIDE
ACHROMATOPSIA ACQUAINTANCES ACROBATICALLY ACTUALISATION ACTUALIZATION
ADAPTABLENESS ADAPTATIONIST ADIABATICALLY ADIATHERMANCY ADVANTAGEABLE
AERODYNAMICAL AGALMATOLITES AGATHODAIMONS AGGRADATIONAL AGGRAVATINGLY
AGGREGATIONAL AIRCRAFTWOMAN ALGEBRAICALLY ALPHABETARIAN AMALGAMATIONS
AMARANTACEOUS AMBASSADORIAL AMINOACIDURIA AMPHIBLASTULA AMPHISTOMATAL
AMPHITHEATRAL AMYGDALACEOUS ANACATHARTICS ANAEROBICALLY ANAGRAMMATISE
ANAGRAMMATISM ANAGRAMMATIST ANAGRAMMATIZE ANALPHABETICS ANALPHABETISM
ANALYSABILITY ANALYZABILITY ANAPHORICALLY ANAPHRODISIAC ANAPHRODISIAS
ANAPHYLACTOID ANASTIGMATISM ANATHEMATICAL ANATHEMATISED ANATHEMATISES
ANATHEMATIZED ANATHEMATIZES ANATOMISATION ANATOMIZATION ANENCEPHALIAS
ANGIOSARCOMAS ANIMALISATION ANIMALIZATION ANOMALISTICAL ANTAGONISABLE
ANTAGONIZABLE ANTASTHMATICS ANTHRANILATES ANTIAIRCRAFTS ANTIALIASINGS
ANTIAPARTHEID ANTIASTHMATIC ANTIBACTERIAL ANTICATALYSTS ANTICIPATABLE
ANTICLASSICAL ANTICOAGULANT ANTIDIARRHEAL ANTIHALATIONS ANTIMACASSARS
ANTIMALARIALS ANTIMARIJUANA ANTINARRATIVE ANTINATIONALS ANTINAUSEANTS
ANTIPARALLELS ANTIPARASITIC ANTIQUITARIAN ANTIRADIATION ANYTHINGARIAN
APATHETICALLY APATOSAURUSES APHRODISIACAL APLANATICALLY APLANOGAMETES
APOCALYPTICAL APOCATASTASES APOCATASTASIS APPEALABILITY APPELLATIONAL
APPERTAINANCE APPOGGIATURAS AQUACEUTICALS ARABICISATION ARABICIZATION
ARACHNOPHOBIA ARAEOMETRICAL ARBITRATIONAL ARCHAEOBOTANY ARCHIDIACONAL
ARCHIPELAGIAN ARCHOSAURIANS ARITHMOMANIAS ARMAMENTARIUM AROMATISATION
AROMATIZATION ASCERTAINABLE ASCERTAINABLY ASPARAGINASES ASSASSINATING
ASSASSINATION ASSASSINATORS ASSOCIATIONAL ASTACOLOGICAL ASTHMATICALLY
ASTRAPOPHOBIA ASTROCYTOMATA ASTRONAUTICAL ATAVISTICALLY ATHEMATICALLY
ATORVASTATINS ATTAINABILITY ATTRACTANCIES AUTHORITARIAN AUTOCATALYSED
AUTOCATALYSES AUTOCATALYSIS AUTOCATALYTIC AUTOCATALYZED AUTOCATALYZES
AUTOGRAPHICAL AUTOMAGICALLY AUTOMATICALLY AUTORADIOGRAM AUTOTOXAEMIAS
AVAILABLENESS AVOCATIONALLY AXIOMATICALLY BACCALAUREATE BACCHANALIANS
BACKWARDATION BALKANISATION BALKANIZATION BALLANWRASSES BALLETOMANIAS
BANALISATIONS BANALIZATIONS BANCASSURANCE BARAESTHESIAS BARBARIANISMS
BARBARISATION BARBARIZATION CABBALISTICAL CACOGRAPHICAL CAESAROPAPISM
CALCULATIONAL CANALICULATED CANALISATIONS CANALIZATIONS CANCELLARIATE
CANTHAXANTHIN CAPACITATIONS CARAVANSARAIS CARAVANSARIES CARAVANSERAIS
CARBAMAZEPINE CARDINALATIAL CARDINALITIAL CARRAGHEENANS CASUALISATION
CASUALIZATION CATABOLICALLY CATALYTICALLY CATAMOUNTAINS CATATONICALLY
CATHARTICALLY CELIBATARIANS CHALAZOGAMIES CHARLATANICAL CHARLATANISMS
CHARLATANRIES CHATEAUBRIAND COADAPTATIONS COASTGUARDMAN CONCANAVALINS
CONTRALATERAL CYANOACRYLATE CYANOBACTERIA DAMAGEABILITY DATAVEILLANCE
DECALCOMANIAS DIAPHRAGMATIC DIPSOMANIACAL DISADVANTAGED DISADVANTAGES
DISAPPEARANCE DISCAPACITATE DRAMATISATION DRAMATIZATION DRAMATURGICAL
EGOMANIACALLY EMBARRASSABLE ENCEPHALALGIA ENCEPHALOMATA EQUALITARIANS
EUPHAUSIACEAN EUTHANASIASTS EXAMINATIONAL EXCLAMATIONAL EXTRAGALACTIC
EXTRAVAGANCES EXTRAVAGANTLY EXTRAVAGANZAS EXTRAVAGATING EXTRAVAGATION
EXTRAVASATING EXTRAVASATION EXTRAVASCULAR FANATICALNESS FANFARONADING
FANTASMICALLY FANTASTICALLY FANTASTICATED FANTASTICATES FARADISATIONS
FARADIZATIONS FARAWAYNESSES FLAGELLOMANIA GALACTAGOGUES GALACTORRHEAS
GALACTORRHOEA GALACTOSAEMIA GALACTOSAEMIC GALACTOSAMINE GALACTOSEMIAS
GALACTOSIDASE GALVANISATION GALVANIZATION GALVANOPLASTY GIGANTOMACHIA
GRADATIONALLY GRAMMATICALLY GRANDPARENTAL GRAVITATIONAL GYNAECOMASTIA
HAEMANGIOMATA HAEMATOBLASTS HANDCRAFTSMAN HAPHAZARDNESS HAPHAZARDRIES
HUMANITARIANS HYPOCALCAEMIA HYPONATRAEMIA IMAGINATIONAL INADAPTATIONS
INCANTATIONAL INCAPACITANTS INCAPACITATED INCAPACITATES INCARNATIONAL
INEGALITARIAN INTRACAPSULAR INTRACAVITARY INTRAGALACTIC INTRANATIONAL
INTRAPARIETAL INTRAVASATION INTRAVASCULAR JALOALLOFANES KATABOLICALLY
KATHAREVOUSAS LABANOTATIONS LABEFACTATION LABIALISATION LABIALIZATION
LACKADAISICAL LACTATIONALLY LALLAPALOOZAS LAMPADEPHORIA LANDGRAVIATES
LOLLAPALOOSAS LOLLAPALOOZAS MACARONICALLY MACHIAVELIANS MACHIAVELLIAN
MACROCEPHALIA MACRODIAGONAL MAGISTRATICAL MAJOLICAWARES MAJORITARIANS
MALACOLOGICAL MALACOSTRACAN MALADAPTATION MALADAPTIVELY MAMMAPLASTIES
MANAGEABILITY MANAGERIALISM MANAGERIALIST MANIPULATABLE MARSUPIALIANS
MASSARANDUBAS MASSERANDUBAS MATERFAMILIAS MATHEMATICIAN MATRIARCHATES
MAXILLOFACIAL MEGALOCARDIAS MEGALOMANIACS MEGALOSAURIAN MEGASPORANGIA
METACERCARIAE METACERCARIAL METACERCARIAS METALANGUAGES METAMATERIALS
METANARRATIVE MISAPPRAISALS NANOMATERIALS NARCOANALYSES NARCOANALYSIS
NASALISATIONS NASALIZATIONS NEOGRAMMARIAN NONAGENARIANS NONANALYTICAL
NONANATOMICAL NONAPPEARANCE NONMAMMALIANS NONMANAGERIAL OSTEOMALACIAL
OSTEOMALACIAS OXALOACETATES PAEDIATRICIAN PAGANISATIONS PAGANIZATIONS
PALAEOBOTANIC PALAEOCLIMATE PALAEOGRAPHER PALAEOGRAPHIC PALATABLENESS
PANAESTHESIAS PANDEMONIACAL PANGRAMMATIST PANOPHTHALMIA PANORAMICALLY
PANPHARMACONS PAPAPRELATIST PAPAVERACEOUS PARABOLANUSES PARABOLICALLY
PARACYANOGENS PARADOXICALLY PARAESTHESIAS PARAGNATHISMS PARAGOGICALLY
PARAGRAPHICAL PARAGRAPHISTS PARAINFLUENZA PARALANGUAGES PARALEIPOMENA
PARALLACTICAL PARALLELOGRAM PARALYSATIONS PARALYTICALLY PARALYZATIONS
PARAMAGNETISM PARANORMALITY PARAPHERNALIA PARAPHRASABLE PARAPOPHYSIAL
PARAPSYCHICAL PARAQUADRATES PARARESCUEMAN PARASEXUALITY PARASITAEMIAS
PARASITICALLY PARASITICIDAL PARLIAMENTARY PASIGRAPHICAL PATERFAMILIAS
PATRIARCHALLY PATRIARCHATES PENTABARBITAL PERMANGANATES PHALANSTERIAN
PHANTASMAGORY PHANTASMALIAN PHANTASMALITY PHARISAICALLY PHARMACOPEIAL
PHARMACOPEIAS PHARMACOPOEIA PIPIWHARAUROA PLASMODESMATA POSTLAPSARIAN
PRAGMATICALLY PREADAPTATION PRELAPSARIANS PROPAGATIONAL QUADRAGESIMAL
QUADRAPLEGIAS QUADRATICALLY QUADRILATERAL RADIALISATION RADIALIZATION
RADIOACTIVATE RAREFACTIONAL RAZZAMATAZZES READAPTATIONS REAPPEARANCES
RHABDOMYOMATA RHADAMANTHINE SACRALISATION SACRALIZATION SACRAMENTALLY
SALAMANDRIANS SALAMANDROIDS SALUTATORIANS SANITARIANISM SARCASTICALLY
SARSAPARILLAS SATANICALNESS SATANOPHANIES SATANOPHOBIAS SATURNALIANLY
SCLEROMALACIA SEXAGENARIANS SQUANDERMANIA STAGECOACHMAN STALACTITICAL
STALAGMITICAL STRAIGHTAWAYS SUBAPPEARANCE SUBLAPSARIANS SUBPARAGRAPHS
SUPRANATIONAL SUPRARATIONAL SYNALLAGMATIC TACHYPHRASIAS TANTALISATION
TANTALIZATION TARAMASALATAS TARATANTARAED TARTARISATION TARTARIZATION
TETRADRACHMAS THALAMIFLORAL THALASSAEMIAS THALASSAEMICS THALASSOCRACY
THALASSOCRATS THALATTOCRACY THANATOGRAPHY THANATOPHOBIA THAUMATOLATRY
THEATROMANIAS TOBACCANALIAN TOTALITARIANS TRADESCANTIAS TRANSACTIONAL
TRANSAMINASES TRANSATLANTIC TRANSLATIONAL TRANSLATORIAL TRANSNATIONAL
TRANSVALUATED TRANSVALUATES TRAUMATICALLY TRAUMATONASTY TRUSTAFARIANS
TURANGAWAEWAE ULTRAFAMILIAR ULTRAMARATHON ULTRANATIONAL ULTRARADICALS
ULTRARATIONAL UNASSUAGEABLE UNGAINSAYABLE UNGRAMMATICAL UNMACADAMISED
UNMACADAMIZED UNSALVAGEABLE UNSALVAGEABLY UNWARRANTABLE UNWARRANTABLY
VACATIONLANDS VALUATIONALLY VANDALISATION VANDALIZATION VARIATIONALLY
VOCABULARIANS