/ Dictionary / Index O oat: Meaning and Definition of Find definitions for: oat Pronunciation: (ōt), [key] a cereal grass, Avena sativa, cultivated for its edible seed. Usually, the seed of this plant, used as a food for humans and animals. any of several plants of the same genus, as the wild oat. a musical pipe made of an oat straw. to feel frisky or lively. to be aware of and use one's importance or power. See(def. 3). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: oat (Thesaurus) oast-house oatcake Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language