12-letter words containing a, t, i, o
- anton sailer — Anton [ahn-tohn] /ˈɑn toʊn/ (Show IPA), ("Toni") 1935–2009, Austrian skier.
- antoninianus — an ancient Roman coin made either of silver or bronze and equal in value to two denarii
- anxious seat — a bench near the preacher at revival meetings, for those with a troubled conscience who seek salvation
- aortic valve — a semilunar valve between the aorta and the left ventricle of the heart that prevents the blood from flowing back into the left ventricle.
- aortographic — relating to an aortography or aortography
- aperiodicity — not periodic; irregular.
- aphoristical — Alternative form of aphoristic.
- apocalyptist — the writer of the Apocalypse or a related work
- apochromatic — (of a lens) almost free from spherical and chromatic aberration
- apodeictical — Apodeictic.
- apolitically — in an apolitical manner
- apostatizing — Present participle of apostatize.
- apostle bird — a gregarious grey-and-brown Australian nest-building bird, Struthidea cinerea
- apostolicity — the quality of being apostolic
- apostrophise — to address by apostrophe.
- apostrophize — to address an apostrophe to
- apothecaries — Plural form of apothecary.
- apothegmatic — Relating to, or in the manner of, an apothegm; sententious; pithy.
- apotheosized — Simple past tense and past participle of apotheosize.
- apparitional — of or relating to an apparition or apparitions; ghostly, spectral
- appassionato — (to be performed) in an impassioned manner
- appellations — Plural form of appellation.
- apperception — the attainment of full awareness of a sensation or idea
- applications — Plural form of application.
- appoggiatura — an ornament consisting of a nonharmonic note (short or long) preceding a harmonic one either before or on the stress
- appointments — Plural form of appointment.
- apportioning — Present participle of apportion.
- appositeness — The state of being apposite.
- appositional — the act of placing together or bringing into proximity; juxtaposition.
- appreciation — Appreciation of something is the recognition and enjoyment of its good qualities.
- appreciators — to be grateful or thankful for: They appreciated his thoughtfulness.
- appreciatory — appreciative.
- approbations — approval; commendation.
- appropriated — suitable or fitting for a particular purpose, person, occasion, etc.: an appropriate example; an appropriate dress.
- appropriates — suitable or fitting for a particular purpose, person, occasion, etc.: an appropriate example; an appropriate dress.
- appropriator — suitable or fitting for a particular purpose, person, occasion, etc.: an appropriate example; an appropriate dress.
- approximated — near or approaching a certain state, condition, goal, or standard.
- approximates — near or approaching a certain state, condition, goal, or standard.
- approximator — Something that approximates.
- apricot tart — a pastry case filled with apricots
- apron string — a string for tying an apron on
- arbitrations — Plural form of arbitration.
- arborization — a branching treelike appearance in certain fossils and minerals
- archaization — Process of becoming or turning something more archaic.
- archegoniate — having archegonia
- archeologist — archaeology.
- archibenthos — the ocean bottom between the littoral and abyssal zones: from depths of approximately 200 feet (60 meters) to 3300 feet (1000 meters).
- arctic ocean — the ocean surrounding the North Pole, north of the Arctic Circle. Area: about 14 100 000 sq km (5 440 000 sq miles)
- arctophilist — a collector of teddy bears
- arfvedsonite — a type of hornblende with the composition Na3(Fe,Mg)4FeSi8O22(OH)2