There are 450 fourteen-letter words containing 3A, https://www.bestwordlist.com/c/a/3/14letterwordswithaaa.htm
ABSQUATULATING ACADEMICALISMS ACATAMATHESIAS ACCLIMATATIONS ACCLIMATISABLE
ACCLIMATIZABLE ACETAZOLAMIDES ACHONDROPLASIA ACHROMATICALLY ACHROMATOPSIAS
ACTUALISATIONS ACTUALIZATIONS ADAPTABILITIES ADAPTATIONALLY ADAPTATIONISTS
ADENOCARCINOMA ADIATHERMANOUS ADVANTAGEOUSLY AEROELASTICIAN AEROMECHANICAL
AERONAUTICALLY AIRCRAFTSWOMAN ALEXIPHARMAKON ALKALINISATION ALKALINIZATION
ALLOPATHICALLY ALLOPATRICALLY ALPHABETARIANS ALPHABETICALLY ALPHAMERICALLY
ALPHANUMERICAL ALTITUDINARIAN AMARANTHACEOUS AMBASSADORSHIP AMBASSADRESSES
AMBULANCEWOMAN AMINOACIDURIAS AMPHIBLASTULAE ANACARDIACEOUS ANACHRONICALLY
ANAGRAMMATICAL ANAGRAMMATISED ANAGRAMMATISES ANAGRAMMATISMS ANAGRAMMATISTS
ANAGRAMMATIZED ANAGRAMMATIZES ANALPHABETISMS ANAMNESTICALLY ANAPHRODISIACS
ANASTIGMATISMS ANATHEMATICALS ANATHEMATISING ANATHEMATIZING ANATOMISATIONS
ANATOMIZATIONS ANGIOSARCOMATA ANIMALISATIONS ANIMALIZATIONS ANTAGONISATION
ANTAGONIZATION ANTAPHRODISIAC ANTIARRHYTHMIA ANTIASTHMATICS ANTIBACTERIALS
ANTIBARBARUSES ANTICAPITALISM ANTICAPITALIST ANTICHLAMYDIAL ANTICOAGULANTS
ANTIDEFAMATION ANTIDIARRHEALS ANTIDIARRHOEAL ANTIHARASSMENT ANTIMANAGEMENT
ANTIMETASTATIC ANTINARRATIVES ANTIPARASITICS ANTIPATHETICAL ANTIPHRASTICAL
ANTIQUARIANISM ANTIQUITARIANS ANTIRADICALISM ANTISEPARATIST ANYTHINGARIANS
APOSEMATICALLY APOTHEGMATICAL APOTROPAICALLY APPERTAINANCES ARABICISATIONS
ARABICIZATIONS ARACHNOLOGICAL ARACHNOPHOBIAS ARCHAEBACTERIA ARCHAEOLOGICAL
ARCHIDIACONATE ARISTOCRATICAL ARMAMENTARIUMS AROMATHERAPIES AROMATHERAPIST
AROMATISATIONS AROMATIZATIONS ASPIRATIONALLY ASSASSINATIONS ASTIGMATICALLY
ASTRAPOPHOBIAS ASTRONAVIGATOR ATTAINABLENESS ATTITUDINARIAN AUTHORITARIANS
AUTOALLOGAMIES AUTOCATALYSING AUTOCATALYZING AUTOCRATICALLY AUTOMATISATION
AUTOMATIZATION AUTORADIOGRAMS AUTORADIOGRAPH AVAILABILITIES AVASCULARITIES
AXIOMATISATION AXIOMATIZATION BACCALAUREATES BACKWARDATIONS BALKANISATIONS
BALKANIZATIONS BALSAMINACEOUS BANCASSURANCES BARBARISATIONS BARBARIZATIONS
BASTARDISATION BASTARDIZATION BATHYGRAPHICAL BATRACHOPHOBIA BIBLIOMANIACAL
BOUGAINVILLAEA BRACHYDIAGONAL BREATHARIANISM CAESAROPAPISMS CALLIGRAPHICAL
CAMOUFLAGEABLE CAMPANOLOGICAL CAMPANULACEOUS CANCELLARIATES CANTHAXANTHINE
CANTHAXANTHINS CAPITALISATION CAPITALIZATION CAPPARIDACEOUS CARAMELISATION
CARAMELIZATION CARBAMAZEPINES CARCINOSARCOMA CARDIOVASCULAR CARPOMETACARPI
CARTOGRAPHICAL CASTRAMETATION CASUALISATIONS CASUALIZATIONS CATACHRESTICAL
CATADIOPTRICAL CATALEPTICALLY CATAPHORICALLY CHAPTALISATION CHAPTALIZATION
CHARLATANISTIC CHATEAUBRIANDS COASTGUARDSMAN CYANOACRYLATES CYANOBACTERIAL
CYANOCOBALAMIN DATAVEILLANCES DERMATOGRAPHIA DIAGONALISABLE DIAGONALIZABLE
DIAGRAMMATICAL DISACCHARIDASE DISADVANTAGING DISAPPEARANCES DISCAPACITATED
DISCAPACITATES DRAMATISATIONS DRAMATIZATIONS EGALITARIANISM ENCEPHALALGIAS
EPIGRAMMATICAL EUPHAUSIACEANS EXTRACANONICAL EXTRAMARITALLY EXTRAPYRAMIDAL
EXTRAVAGANCIES EXTRAVAGATIONS EXTRAVASATIONS FANATICISATION FANATICIZATION
FANTASTICALITY FANTASTICATING FANTASTICATION FATALISTICALLY FIBROSARCOMATA
FLAGELLOMANIAC FLAGELLOMANIAS GALACTORRHOEAS GALACTOSAEMIAS GALACTOSAMINES
GALACTOSIDASES GALVANISATIONS GALVANIZATIONS GALVANOPLASTIC GASTROVASCULAR
GIGANTOMACHIAS GLIOBLASTOMATA GRAMMATICALITY GRAMMATICASTER GYNAECOMASTIAS
HAEMATOBLASTIC HAEMATOLOGICAL HAEMATOPHAGOUS HAEMATOTHERMAL HAGIOGRAPHICAL
HANDICRAFTSMAN HEPATOPANCREAS HYPERCALCAEMIA HYPERNATRAEMIA HYPERSARCOMATA
HYPOCALCAEMIAS HYPONATRAEMIAS INAPPROACHABLE INAPPROACHABLY INCAPACITATING
INCAPACITATION INEGALITARIANS INFRALAPSARIAN INFRAMAXILLARY INTERAMBULACRA
INTERAVAILABLE INTRACARDIALLY INTRACRANIALLY INTRAFALLOPIAN INTRAVASATIONS
LABEFACTATIONS LABIALISATIONS LABIALIZATIONS LAMPADEPHORIAS LAMPADOMANCIES
LATERALISATION LATERALIZATION LATITUDINARIAN LYMPHANGIOMATA MACADAMISATION
MACADAMIZATION MACHIAVELLIANS MACRENCEPHALIA MACROAGGREGATE MACROCEPHALIAS
MACRODIAGONALS MACROSPORANGIA MALACOSTRACANS MALACOSTRACOUS MALADAPTATIONS
MALAPPROPRIATE MANAGEABLENESS MANAGERIALISMS MANAGERIALISTS MANUFACTURABLE
MATHEMATICALLY MATHEMATICIANS MATRESFAMILIAS MATRIARCHALISM MEGALOMANIACAL
MEGALOSAURIANS METANARRATIVES METAPHRASTICAL METASTATICALLY MISCELLANARIAN
MONOMANIACALLY MORGANATICALLY NARCOCATHARSES NARCOCATHARSIS NARRATOLOGICAL
NASOPHARYNGEAL NATURALISATION NATURALIZATION NAVIGATIONALLY NEOGRAMMARIANS
NONAPPEARANCES NONGRAMMATICAL NYMPHOMANIACAL ORGANISATIONAL ORGANIZATIONAL
OSTEOSARCOMATA OVERANALYTICAL PAEDIATRICIANS PAGANISTICALLY PALAEANTHROPIC
PALAEOBOTANIES PALAEOBOTANIST PALAEOCLIMATES PALAEOCLIMATIC PALAEOGRAPHERS
PALAEOGRAPHIES PALAEOGRAPHIST PALAEOMAGNETIC PALATABILITIES PALATALISATION
PALATALIZATION PALATIALNESSES PALEOBOTANICAL PALEOGRAPHICAL PALMATIPARTITE
PANGRAMMATISTS PANOPHTHALMIAS PANTOGRAPHICAL PANTOPRAGMATIC PAPAPRELATISTS
PARABIOTICALLY PARABOLISATION PARABOLIZATION PARADIGMATICAL PARADISAICALLY
PARADISIACALLY PARADOXICALITY PARAGRAMMATIST PARAINFLUENZAS PARAJOURNALISM
PARALLELOGRAMS PARAMAGNETISMS PARAMETRICALLY PARAMILITARIES PARAPHRASTICAL
PARAROSANILINE PARASITISATION PARASITIZATION PARATACTICALLY PARONOMASTICAL
PATRESFAMILIAS PATRIALISATION PATRIALIZATION PATRIARCHALISM PENTABARBITALS
PHALANSTERIANS PHANTASMAGORIA PHANTASMAGORIC PHANTASMICALLY PHARMACEUTICAL
PHARMACOPOEIAL PHARMACOPOEIAN PHARMACOPOEIAS PIPIWHARAUROAS POSTLAPSARIANS
PRAGMATICALITY PRAGMATISATION PRAGMATIZATION PREADAPTATIONS QUADRAGENARIAN
QUADRANGULARLY QUADRILATERALS QUAQUAVERSALLY RADIALISATIONS RADIALIZATIONS
RADICALISATION RADICALIZATION RADIOACTIVATED RADIOACTIVATES RADIOAUTOGRAPH
RANGATIRATANGA RAREFICATIONAL RATIONALISABLE RATIONALIZABLE REACQUAINTANCE
RECANALISATION RECANALIZATION SACCHARISATION SACCHARIZATION SACRALISATIONS
SACRALIZATIONS SACRAMENTALISM SACRAMENTALIST SACRAMENTALITY SACRAMENTARIAN
SACRAMENTARIES SALVAGEABILITY SANITARIANISMS SAXIFRAGACEOUS SCANDALISATION
SCANDALIZATION SCLEROMALACIAS SEPTUAGENARIAN SPATIALISATION SPATIALIZATION
SQUANDERMANIAS STAGFLATIONARY SUBAPPEARANCES SUBARACHNOIDAL SUPRALAPSARIAN
SUPRAMAXILLARY TABULARISATION TABULARIZATION TACHYGRAPHICAL TALISMANICALLY
TANTALISATIONS TANTALIZATIONS TARATANTARAING TARSOMETATARSI TARTARISATIONS
TARTARIZATIONS TELANGIECTASIA TETRAGRAMMATON TETRASPORANGIA THALASSOGRAPHY
THANATOLOGICAL THANATOPHOBIAS THAUMATOGRAPHY THAUMATROPICAL THAUMATURGICAL
TOBACCANALIANS TRANSABDOMINAL TRANSAMINATION TRANSCAUCASIAN TRANSPLACENTAL
TRANSPLANTABLE TRANSVALUATING TRANSVALUATION TRAUMATISATION TRAUMATIZATION
TURANGAWAEWAES ULTRAHAZARDOUS ULTRAMARATHONS ULTRAPRACTICAL UNACADEMICALLY
UNACQUAINTANCE UNADAPTABILITY UNAPPROACHABLE UNAPPROACHABLY UNAVAILABILITY
UNDRAMATICALLY UNMAINTAINABLE UNMARRIAGEABLE UNMATHEMATICAL UNPALATABILITY
UNTRANSLATABLE UNTRANSLATABLY URANOGRAPHICAL VALERIANACEOUS VALETUDINARIAN
VANDALISATIONS VANDALIZATIONS VASODILATATION VASODILATATORY WARRANTABILITY