There are 597 thirteen-letter words containing A, 2O, P and T, https://www.bestwordlist.com/c/a/5/13letterwordswithaoopt.htm ACHROMATOPSIA ACTINOMORPHIC ADRENOCEPTORS AEROPLANKTONS AETHRIOSCOPES ANISOMETROPIA ANISOMETROPIC ANISOTROPISMS ANTEPOSITIONS ANTHROPOGENIC ANTHROPOLATRY ANTHROPOMETRY ANTHROPOMORPH ANTHROPOPATHY ANTHROPOPHAGI ANTHROPOPHAGY ANTHROPOPHYTE ANTHROPOSOPHY ANTICORPORATE ANTIGROPELOES ANTIPOLLUTION ANTISTROPHONS AORTOGRAPHIES APHELIOTROPIC APOCHROMATISM APOGEOTROPISM APOSTOLICALLY APOSTOLICISMS APOSTROPHISED APOSTROPHISES APOSTROPHIZED APOSTROPHIZES APOSTROPHUSES APOTHEOSISING APOTHEOSIZING APPORTIONABLE APPORTIONMENT APPROPRIATION APPROPRIATORS APPROXIMATION ARITHMOPHOBIA ARTHROSCOPIES ARTHROSPOROUS ASTRAPOPHOBIA AUTOBIOGRAPHY AUTOCEPHALOUS AUTOCOMPLETES AUTOEXPOSURES AUTOMORPHISMS AUTOPOLYPLOID BALLISTOSPORE BARORECEPTORS BIOCOMPATIBLE BOOTSTRAPPERS BOOTSTRAPPING CALCIPOTRIOLS CAMPANOLOGIST CATHODOGRAPHS CATHODOGRAPHY CEPHALOTHORAX CEPHALOTOMIES CHEMAUTOTROPH CHEMOAUTROPHS CHIROPRACTORS CHLOROPLASTAL CHLOROPLASTIC CHROMATOGRAPH CHROMATOPHORE CHROMATOPSIAS CHROMOTHERAPY CHRONOTHERAPY CLAUSTROPHOBE COADAPTATIONS COADJUTORSHIP COAUTHORSHIPS COCONSPIRATOR COMPAGINATION COMPASSIONATE COMPATRIOTISM COMPELLATIONS COMPENSATIONS COMPLANATIONS COMPLEXATIONS COMPLICATIONS COMPOSITIONAL COMPOSITORIAL COMPURGATIONS COMPUTATIONAL CONCORPORATED CONCORPORATES CONSPIRATIONS CONSPURCATION CONSTIPATIONS CONSTUPRATION CONTAINERPORT CONTEMPLATION CONTEMPLATORS CONTRACEPTION CONTRAPPOSTOS CONVERTOPLANE COOPERATIVELY COOPERATIVITY COPROPHAGISTS CORPORALITIES CORPORATENESS CORPORATISING CORPORATIVISM CORPORATIZING CORPOREALISTS COSMOGRAPHIST COSMOPOLITANS COTRANSPORTED COTRANSPORTER CRANIOSCOPIST CRYOPLANKTONS CRYPTOLOGICAL CYTOPATHOLOGY DEOPPILATIONS DEPOPULATIONS DEPOSITATIONS DESPOLIATIONS DIAGEOTROPISM DIAPHOTOTROPY DIPLOMATOLOGY DISCORPORATED DISCORPORATES DISOPERATIONS DISPOSITIONAL DODECAPHONIST DRAUGHTPROOFS ENANTIOMORPHS ENANTIOMORPHY ENANTIOTROPIC ENCEPHALOTOMY ENTOMOPHAGIES ENTOMOPHAGOUS EPIDOTISATION EPIDOTIZATION EPITOMISATION EPITOMIZATION EPIZOOTICALLY ERGATOMORPHIC ERYTHROPHOBIA ESCAPOLOGISTS EVAPOROMETERS EXPECTORATION EXPECTORATORS EXPLOITATIONS EXPLORATIONAL EXPOSTULATION EXPOSTULATORS EXPOSTULATORY EXPROBRATIONS EXPROPRIATION EXPROPRIATORS EXTRAPOLATION EXTRAPOLATORS EXTRAPOLATORY EXTRAPOSITION FLAVOPROTEINS GALVANOTROPIC GASTEROPODOUS GASTROSCOPIES GASTROSCOPIST GASTROSOPHERS GASTROSOPHIES GEOPOLITICIAN GEOTROPICALLY GERONTOPHILIA GERONTOPHOBIA GONADOTROPHIC GONADOTROPHIN GONADOTROPINS GRAMOPHONISTS GRAPHOLOGISTS HAEMOPROTEINS HAPTOTROPISMS HELIOTROPICAL HEMATOPHAGOUS HEMATOPOIESES HEMATOPOIESIS HEMATOPOIETIC HEPATOLOGISTS HEPATOSCOPIES HETEROCARPOUS HIPPOPOTAMIAN HOLOPARASITES HOLOPARASITIC HOLOPLANKTONS HOMEOPATHISTS HOMOEOPATHIES HOMOEOPATHIST HOMOEOTYPICAL HORRIPILATION HYPNOTISATION HYPNOTIZATION HYPOPHOSPHATE HYPOTHECATION HYPOTHECATORS IMPERFORATION IMPERSONATION IMPERSONATORS IMPIGNORATION IMPOSTUMATION IMPROPRIATION IMPROPRIATORS IMPROVISATION IMPROVISATORE IMPROVISATORI IMPROVISATORS IMPROVISATORY INCORPORATING INCORPORATION INCORPORATIVE INCORPORATORS INFRAPOSITION INOCCUPATIONS INTERPOLATION INTERPOLATORS ISOTROPICALLY JUXTAPOSITION LACTOPROTEINS LAPAROSCOPIST LYMPHOMATOSES LYMPHOMATOSIS MALABSORPTION MASTIGOPHORAN MASTIGOPHORES MASTIGOPHORIC MEGALOPOLITAN MELANOTROPINS MEROPLANKTONS METALLOPHONES METAMORPHOSED METAMORPHOSES METAMORPHOSIS METEOROGRAPHS METROPOLITANS MICROPLANKTON MODERATORSHIP MONOGRAPHISTS MONOPHOSPHATE MONOPHTHONGAL MONOTHERAPIES MYCETOPHAGOUS MYTHOPOETICAL NANNOPLANKTON NANOCOMPOSITE NANOPLANKTONS NONABSORPTIVE NONCOMPATIBLE NONCONCEPTUAL NONCOOPERATOR NONDIPLOMATIC NONPATHOGENIC NONPHOSPHATES NONPOLITICIAN ODONTOPHOBIAS ODONTOPHORANS OMMATOPHOROUS OMOPLATOSCOPY ONOMATOPOEIAS ONOMATOPOESES ONOMATOPOESIS ONOMATOPOETIC ONYCHOPHAGIST OPERATIONALLY OPERATIONISMS OPERATIONISTS OPHTHALMOLOGY OPINIONATEDLY OPISTHOBRANCH OPISTHOGRAPHS OPISTHOGRAPHY OPISTHOSOMATA OPPIGNERATION OPPIGNORATING OPPIGNORATION OPSONISATIONS OPSONIZATIONS OPTIMISATIONS OPTIMIZATIONS OPTIONALITIES ORGANOTHERAPY ORNITHOPHOBIA ORTHOCEPHALIC ORTHOEPICALLY ORTHOGRAPHERS ORTHOGRAPHIES ORTHOGRAPHIST ORTHOPAEDICAL ORTHOPAEDISTS ORTHOPINAKOID OSTEOGRAPHIES OSTEOPATHISTS OSTEOPLASTIES OSTREOPHAGIES OSTREOPHAGOUS OUTPASSIONING OUTPOPULATING OVEROPERATING OVERPOPULATED OVERPOPULATES OVIPOSITIONAL OVOVIVIPARITY PAEDOTROPHIES PALAEOBOTANIC PALAEONTOLOGY PALEOBOTANIES PALEOBOTANIST PALEONTOLOGIC PALLIDOTOMIES PALYNOLOGISTS PANTHEOLOGIES PANTHEOLOGIST PAPILLOMATOUS PAPYROLOGISTS PARASITOLOGIC PARATHORMONES PARTHENOSPORE PARTICOLOURED PATHOGNOMONIC PATHOLOGISING PATHOLOGIZING PATRONISATION PATRONIZATION PEPTONISATION PEPTONIZATION PERFOLIATIONS PERIODISATION PERIODIZATION PERIODONTALLY PERNOCTATIONS PEROXIDATIONS PHAGOCYTOSING PHLEBOTOMICAL PHONAUTOGRAPH PHONETISATION PHONETIZATION PHONOCAMPTICS PHONOGRAPHIST PHONOMETRICAL PHOSPHORATING PHOSPHORYLATE PHOTOCATHODES PHOTOCHEMICAL PHOTOCOPIABLE PHOTODYNAMICS PHOTOENGRAVED PHOTOENGRAVER PHOTOENGRAVES PHOTOGELATINE PHOTOGRAPHERS PHOTOGRAPHIES PHOTOGRAPHING PHOTOGRAPHIST PHOTOGRAVURES PHOTOMACHINES PHOTOMONTAGES PHOTONEGATIVE PHOTOREACTION PHOTOREACTIVE PHOTOREALISMS PHOTOREALISTS PHOTOSCANNING PHOTOSTATTING PHOTOSYNTHATE PHOTOTELEGRAM PHOTOVOLTAICS PHRASEOLOGIST PHYTONADIONES PHYTOPATHOGEN PHYTOPLANKTON PLAGIOSTOMOUS PLAGIOTROPISM PLAGIOTROPOUS PLANETOLOGIES PLANETOLOGIST PLASTOQUINONE PNEUMATOPHORE POCOCURANTISM POCOCURANTIST PODSOLISATION PODSOLIZATION PODZOLISATION PODZOLIZATION POLARISATIONS POLARIZATIONS POLLICITATION POLYCARBONATE POLYCHROMATIC POLYDACTYLOUS POLYHISTORIAN POLYTHALAMOUS POLYTONALISMS POLYTONALISTS PONTIFICATION PONTIFICATORS PORNIFICATION POSSESSIONATE POSTCONCILIAR POSTDOCTORALS POSTDOCTORATE POSTEMBRYONAL POSTERISATION POSTERIZATION POSTHOLOCAUST POSTILLATIONS POSTISOLATION POSTMENOPAUSE POSTOPERATIVE POSTROMANTICS POSTSECONDARY POSTULATIONAL POSTVASECTOMY POTAMOLOGICAL POTAMOLOGISTS POTENTIATIONS POTICHOMANIAS POWERBOATINGS PREADMONITION PREADULTHOODS PRECONISATION PRECONIZATION PRECOPULATORY PREDOMINATION PREDOMINATORS PREFLORATIONS PREFOLIATIONS PREFORMATIONS PRENOMINATION PREOCCUPATION PREORDINATION PREPOSITIONAL PREVOCATIONAL PRIMATOLOGIES PRIMATOLOGIST PROBATIONALLY PROCLAMATIONS PROCONSULATES PROCREATIONAL PROCTOLOGICAL PROCURATORIAL PROCURATORIES PROFESSORATES PROFESSORIATE PROFESSORIATS PROGENITORIAL PROGLOTTIDEAN PROGNOSTICATE PROGRADATIONS PROLIFERATION PROLIFICATION PROLONGATIONS PROMONARCHIST PROMOTABILITY PROMULGATIONS PRONUNCIATION PROPAGATIONAL PROPAROXYTONE PROPITIATIONS PROPITIATIOUS PROPORTIONALS PROPORTIONATE PROPOSITIONAL PROPRAETORIAL PROPRAETORIAN PROPRIETORIAL PROPUGNATIONS PROSECUTORIAL PROSTATECTOMY PROSTHODONTIA PROTANOMALIES PROTANOMALOUS PROTECTORATES PROTEINACEOUS PROTEOCLASTIC PROTEOGLYCANS PROTERANDROUS PROTESTATIONS PROTOACTINIUM PROTOCERATOPS PROTOCHORDATE PROTOGALAXIES PROTOLANGUAGE PROTONOTARIAL PROTONOTARIAT PROTONOTARIES PROTOSPATAIRE PROTOTHERIANS PROTUBERATION PROVOCATIVELY PSYCHOSOMATIC PTOCHOCRACIES PYROCATECHOLS PYROPHOSPHATE RADIOISOTOPES RADIOISOTOPIC RADIOPHONISTS REABSORPTIONS REAPPORTIONED RECIPROCATION RECIPROCATORS RECIPROCATORY RECOMPILATION RECOMPUTATION REEXPLORATION REEXPORTATION REIMPORTATION REINCORPORATE REOCCUPATIONS REPHOTOGRAPHS REPOPULATIONS REPORTORIALLY RHYTHMOPOEIAS RONTGENOGRAPH RONTGENOPAQUE SATANOPHOBIAS SCOPTOPHILIAS SCOPTOPHOBIAS SEXPLOITATION SHARPSHOOTERS SHARPSHOOTING SNAPSHOOTINGS SOMATOPLASTIC SOMATOPLEURAL SOMATOPLEURES SOMATOPLEURIC SOMATOTROPHIC SOMATOTROPHIN SOMATOTROPINE SOMATOTROPINS SOPHISTICATOR SOUSAPHONISTS SPELAEOLOGIST SPERMATOGONIA SPERMATOPHORE SPERMATOZOANS SPERMATOZOIDS SPHAGNOLOGIST SPLAYFOOTEDLY SPONGIOBLASTS SPONTANEOUSLY STAPHYLOCOCCI STEGANOPODOUS STENOPETALOUS STOMATOPLASTY STREPTOCOCCAL STROPHIOLATED SUBPOPULATION SULPHONATIONS SUPEREROGATOR SUPPOSITIONAL TABLESPOONFUL TACHISTOSCOPE TAUROMORPHOUS TAUTOPHONICAL TECHNOPHOBIAS TECHNOPOLITAN TELEPORTATION TEMPORISATION TEMPORIZATION TERATOPHOBIAS THANATOPHOBIA THEATROPHONES THORACOPLASTY THORACOSCOPES THOROUGHPACED THROMBOPHILIA TOPOGRAPHICAL TOPOISOMERASE TOPOLOGICALLY TOTIPALMATION TOXICOPHAGOUS TOXICOPHOBIAS TOXOPLASMOSES TOXOPLASMOSIS TRANSPOSITION TRAPEZOHEDRON TRAPSHOOTINGS TREPONEMATOUS TRICORPORATED TROPHOBLASTIC TROPOCOLLAGEN TROPOSCATTERS TYPOLOGICALLY UNAPOSTOLICAL UNCOOPERATIVE UNPROVOCATIVE VAPORISATIONS VAPORIZATIONS VELOCIRAPTORS WATERPROOFERS WATERPROOFING WEAPONIZATION WEATHERPROOFS ZOOPLANKTONIC