/ Dictionary / Index O ONR: Meaning and Definition of Find definitions for: ONR Pronunciation: [key] Office of Naval Research. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. on-peak on-ramp Related Content Daily Word Quiz: impetuous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language