9-letter words containing i, s, a, t, o
- ocularist — a person who makes artificial eyes
- odonatist — a person who studies or is expert in insects that belong to the zoological group Odonata
- olfactics — The study of smells and how they are perceived.
- onanistic — withdrawal of the penis in sexual intercourse so that ejaculation takes place outside the vagina; coitus interruptus.
- onomastic — of or relating to proper names.
- opacities — the state or quality of being opaque.
- operatics — Exaggerated or overly emotional behaviour; histrionics.
- optatives — Plural form of optative.
- opticians — Plural form of optician.
- oratories — Plural form of oratory.
- oratorios — Plural form of oratorio.
- ordinates — Plural form of ordinate.
- organists — Plural form of organist.
- orgiastic — of, relating to, or having the nature of an orgy.
- orientals — Plural form of oriental.
- origamist — A person who does origami.
- orleanist — a supporter of the Orléans branch of the former French royal family and of its claim to the throne of France through descent from the younger brother of Louis XIV.
- orthoaxis — the axis in a crystal
- oscillate — to swing or move to and fro, as a pendulum does.
- oscitancy — yawning, as with drowsiness; gaping.
- osmeteria — glands in some caterpillars that secrete foul-smelling substances to deter predators
- ostealgia — (pathology) bone pain.
- ostiaries — Plural form of ostiary.
- ostinatos — Plural form of ostinato.
- ostracise — to exclude, by general consent, from society, friendship, conversation, privileges, etc.: His friends ostracized him after his father's arrest.
- ostracism — exclusion, by general consent, from social acceptance, privileges, friendship, etc.
- ostracize — to exclude, by general consent, from society, friendship, conversation, privileges, etc.: His friends ostracized him after his father's arrest.
- ostrasize — Misspelling of ostracize.
- outparish — a parish located outside the boundaries of or at a distance from a town or city; an outlying parish.
- outraised — Simple past tense and past participle of outraise.
- outsailed — Simple past tense and past participle of outsail.
- outstrain — to strain or stretch too much
- overstain — to stain too much
- ozostomia — bad breath; halitosis.
- panoistic — (of insects) producing ova without cells to nurse them
- pantihose — (used with a plural verb) a one-piece, skintight garment worn by women, combining panties and stockings.
- parotitis — inflammation of a parotid.
- pasticcio — a pastiche.
- pastitsio — a Greek dish consisting of minced meat and macaroni topped with béchamel sauce
- pastoring — a minister or priest in charge of a church.
- pastorium — a Baptist parsonage.
- pastosity — having a heavy impasto.
- patronise — to give (a store, restaurant, hotel, etc.) one's regular patronage; trade with.
- periaktos — an ancient device used for changing theatre scenery, usually consisting of a revolving triangular prism with different scenes painted on each face; the device was heavily used in the Renaissance
- peronista — Peronist.
- petrosian — Tigran (tiɡˈran). 1929–84, Soviet chess player; world champion (1963–69)
- photopsia — a rare disease of the eye's retina that results in the perception of flashes of light
- pianolist — a person who plays the Pianola
- piscatory — of or relating to fishermen or fishing: a piscatory treaty.
- pistachio — the nut of a Eurasian tree, Pistacia vera, of the cashew family, containing an edible, greenish kernel.