/ Dictionary / Index U USNA: Meaning and Definition of Find definitions for: USNA Pronunciation: [key] United States National Army. United States Naval Academy. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. USN usnea 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