/ Dictionary / Index U USNR: Meaning and Definition of Find definitions for: USNR Pronunciation: [key] United States Naval Reserve. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. usnic acid USO 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