/ Dictionary / Index O oat grass: Meaning and Definition of Find definitions for: oat' grass" Pronunciation: [key] any of several grasses of the genus Arrhenatherum or Danthonia, esp. A. elatius, native to Europe, having a purplish-green flowering panicle. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Oates oath Related Content Daily Word Quiz: fidelity Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language