/ Dictionary / Index O oater: Meaning and Definition of Find definitions for: oat•er Pronunciation: (ō'tur), [key] — n. Slang. a movie, television show, etc., about the frontier days of the U.S. West; western; horse opera. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. oaten Oates Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language