There are 443 thirteen-letter words containing 2A, I, T and Y, https://www.bestwordlist.com/c/a/5/13letterwordswithaaity.htm
ABORIGINALITY ABSORBABILITY ABSTRACTIVELY ACCEPTABILITY ACCIDENTALITY
ACCOMPANYISTS ACHROMATICITY ACQUIRABILITY ACROBATICALLY ACTINOTHERAPY
ADDITIONALITY ADIABATICALLY ADIATHERMANCY ADJUSTABILITY ADSORBABILITY
ADUMBRATIVELY ADVERSATIVELY AESTHETICALLY AFFECTABILITY AFFECTIONALLY
AFFIRMATIVELY AFFORDABILITY AGGRAVATINGLY AGGREGATIVELY AGONISTICALLY
AHISTORICALLY ALLOTYPICALLY ALTERNATINGLY ALTERNATIVELY AMBISEXUALITY
ANALYSABILITY ANALYTICITIES ANALYZABILITY ANAPHYLACTOID ANECDOTICALLY
ANFRACTUOSITY ANONYMISATION ANONYMIZATION ANSWERABILITY ANTHRACYCLINE
ANTIAUTHORITY ANTICATALYSTS ANTIGENICALLY ANTINOMICALLY ANTIPREDATORY
ANTIROYALISTS ANTISEXUALITY ANTISOCIALITY ANTITYPICALLY ANYTHINGARIAN
APATHETICALLY APLANATICALLY APOCALYPTICAL APOCALYPTISMS APOCALYPTISTS
APODICTICALLY APOLITICALITY APOMICTICALLY APOSTOLICALLY APPEALABILITY
APPELLATIVELY APPLICABILITY APPLICATIVELY APPROPRIATELY APPROXIMATELY
APTITUDINALLY ARTERIOGRAPHY ARTHRITICALLY ARTIFICIALITY ASCERTAINABLY
ASPHYXIATIONS ASSIGNABILITY ASSOCIABILITY ASSOCIATIVELY ASSOCIATIVITY
ASSORTATIVELY ASTHMATICALLY ASTRODYNAMICS ASTROPHYSICAL ASYNDETICALLY
ATAVISTICALLY ATHEISTICALLY ATHEMATICALLY ATOMISTICALLY ATTAINABILITY
ATTITUDINALLY ATYPICALITIES AUTHENTICALLY AUTOBIOGRAPHY AUTOCATALYSIS
AUTOCATALYTIC AUTOMAGICALLY AUTOMATICALLY AUTONOMICALLY AUTOSTABILITY
AVOCATIONALLY AXIOMATICALLY AYUNTAMIENTOS BACTERIOPHAGY BALLISTICALLY
BATHYMETRICAL BIOSTATICALLY BOMBASTICALLY BREATHABILITY BREATHALYSING
BREATHALYZING CALCULABILITY CALCULATINGLY CAPTIVATINGLY CARBONYLATING
CARBONYLATION CARBOXYLATING CARBOXYLATION CASUISTICALLY CATABOLICALLY
CATALYTICALLY CATATONICALLY CATEGORICALLY CATHARTICALLY CHANGEABILITY
CHARGEABILITY CHROMATICALLY CINEMATICALLY CLADISTICALLY CLAIRVOYANTLY
CLAVICYTHERIA CLIMACTICALLY CLIMATOGRAPHY COAGULABILITY COLLATERALITY
COMPARABILITY COMPARATIVELY COMPLAISANTLY CONNATURALITY CRYPTANALYSIS
CRYPTANALYTIC CRYSTALISABLE CRYSTALIZABLE CRYSTALLOIDAL CYANOBACTERIA
CYTOCHALASINS DACTYLIOMANCY DAMAGEABILITY DECLAMATORILY DECLARATIVELY
DECLARATORILY DEGRADABILITY DETACHABILITY DEVASTATINGLY DIACRITICALLY
DIALECTICALLY DIALYPETALOUS DIALYSABILITY DIALYZABILITY DIAMETRICALLY
DICTATORIALLY DUALISTICALLY DYSAESTHESIAS EDUCATABILITY EDUCATIONALLY
ENCAUSTICALLY ENHYPOSTASIAS ENIGMATICALLY ENZYMATICALLY EPINASTICALLY
EQUILATERALLY EVANGELISTARY EVAPORABILITY EXAMINABILITY EXCLAMATORILY
EXPANDABILITY EXPLANATIVELY EXPLANATORILY EXTRALIMITARY EXTRALITERARY
EXTRAORDINARY FACTORABILITY FACULTATIVELY FANTASMICALLY FANTASTICALLY
FASCICULATELY FASCINATINGLY FASCISTICALLY FAUNISTICALLY FORESTAYSAILS
FOUNDATIONARY FRAGMENTARILY GEOSTATIONARY GEOTACTICALLY GNATHONICALLY
GRADATIONALLY GRAMMATICALLY GYMNASTICALLY GYNAECOCRATIC GYNAECOMASTIA
GYNECOMASTIAS HAEMATOXYLINS HALLUCINATORY HEPTASYLLABIC HYALINISATION
HYALINIZATION HYDROPATHICAL HYDROSTATICAL HYPAESTHESIAS HYPERPARASITE
HYPERRATIONAL HYPNOANALYTIC HYPONATRAEMIA HYPONATRAEMIC HYPONATREMIAS
HYSTEROMANIAS ICHTHYOFAUNAE ICHTHYOFAUNAL ICHTHYOFAUNAS IDIOMATICALLY
IMAGINATIVELY IMAGISTICALLY IMMATERIALITY IMPALPABILITY IMPASSABILITY
IMPLACABILITY IMPRACTICABLY IMPRACTICALLY INDEFATIGABLY INELABORATELY
INELASTICALLY INSATIABILITY INSTANTANEITY INTERCALARILY INTERFACIALLY
INTERRACIALLY INTERRADIALLY INTRACAVITARY INTRADERMALLY INTRAOCULARLY
INTRATHECALLY INVARIABILITY IPSILATERALLY IRRATIONALITY ISOSTATICALLY
JUDGMATICALLY KATABOLICALLY KINEMATICALLY LABYRINTHICAL LACHRYMATIONS
LACTATIONALLY LATITUDINALLY LETHARGICALLY LYMPHATICALLY MACHINABILITY
MACRODACTYLIC MAGISTERIALLY MALADAPTIVELY MANAGEABILITY MARKETABILITY
MARTYRISATION MARTYRIZATION MATRICULATORY MATRIFOCALITY MATRILINEALLY
MATRILOCALITY MATRIMONIALLY MEASURABILITY MEDIATORIALLY MEDICAMENTARY
MESATICEPHALY METABOLICALLY METAMERICALLY METAPHYSICIAN METAPSYCHICAL
METASTABILITY MICROANALYSTS MICROANALYTIC MULTIRACIALLY MUTAGENICALLY
MYCOBACTERIAL NAPHTHYLAMINE NOMINATIVALLY NONANALYTICAL NONSTATIONARY
NOSTALGICALLY OBTAINABILITY OCCASIONALITY ONOMASTICALLY OPERATIONALLY
ORGIASTICALLY PAINSTAKINGLY PALAEOCRYSTIC PANCYTOPENIAS PARALYSATIONS
PARALYTICALLY PARALYZATIONS PARANORMALITY PARASEXUALITY PARASITICALLY
PARASYMBIONTS PARASYMBIOTIC PARASYNTHESIS PARASYNTHETIC PARLIAMENTARY
PARTICIPANTLY PARTICIPATORY PARTICIPIALLY PARTICULARITY PATENTABILITY
PATRIARCHALLY PATRIFOCALITY PATRILINEALLY PATRILINEARLY PATRIMONIALLY
PATRIOTICALLY PATRISTICALLY PEIRASTICALLY PENTADACTYLIC PENTASYLLABIC
PHANTASMALITY PHTHALOCYANIN PHYLACTERICAL PHYTOSANITARY PIANISTICALLY
PISCATORIALLY PLASTOCYANINS PLATINOCYANIC PLATYCEPHALIC PLATYRRHINIAN
PLAYABILITIES PNEUMATICALLY POLYCYTHAEMIA POSTCRANIALLY PRAGMATICALLY
PRECAUTIONARY PREFATORIALLY PREPARATIVELY PREPARATORILY PRISMATICALLY
PROBATIONALLY PROPAGABILITY PSYCHASTHENIA PSYCHIATRICAL PURGATORIALLY
PURITANICALLY QUADRATICALLY QUALIFICATORY QUALITATIVELY QUASICRYSTALS
RADICULOPATHY RADIOACTIVELY RADIOACTIVITY RATIOCINATORY REALISABILITY
REALISTICALLY REALIZABILITY REASONABILITY REBARBATIVELY RECALCITRANCY
RECALLABILITY REMARKABILITY REPAIRABILITY REPEATABILITY REVEALABILITY
RHEUMATICALLY ROMANTICALITY SACCHARIMETRY SACROSANCTITY SARCASTICALLY
SATURNALIANLY SCHEMATICALLY SEARCHABILITY SEASONABILITY SENSATIONALLY
SITUATIONALLY SPERMATICALLY SPREADABILITY STAPHYLINIDAE STATISTICALLY
STAYCATIONERS STIGMATICALLY STRAIGHTAWAYS STRAITLACEDLY STRATEGICALLY
SUBSTANTIALLY SYBARITICALLY SYCOPHANTICAL SYLLABICATING SYLLABICATION
SYMPATHETICAL SYMPATRICALLY SYMPTOMATICAL SYNAESTHESIAS SYNALLAGMATIC
SYNAPOSEMATIC SYNARTHRODIAL SYNTACTICALLY SYNTACTICIANS SYNTAGMATITES
SYSTEMATICIAN TACHYGRAPHIES TACHYGRAPHIST TACHYMETRICAL TACHYPHRASIAS
TACHYPHYLAXIS TANGENTIALITY TANTALISINGLY TANTALIZINGLY TAUTOSYLLABIC
TAXONOMICALLY TETRABASICITY TETRASYLLABIC THEATRICALITY THRASONICALLY
TRADITIONALLY TRANSEXUALITY TRANSITIONARY TRANSMITTANCY TRANSPIRATORY
TRAUMATICALLY TRIANGULARITY TRIANGULATELY TRIATOMICALLY TRICARPELLARY
TRISYLLABICAL TRYPAFLAVINES TRYPARSAMIDES TYPOGRAPHICAL TYRANNOSAURID
ULTRAPHYSICAL ULTRAROYALIST UNFAMILIARITY UNILATERALITY UNIPARENTALLY
UNMISTAKEABLY UNPRACTICALLY UNREADABILITY UNSALEABILITY UNSUSTAINABLY
UPGRADABILITY VACILLATINGLY VALUATIONALLY VAPOURABILITY VARIATIONALLY
VERNACULARITY YACHTSMANSHIP ZEUGMATICALLY