/ Dictionary / Index U unsuccess: Meaning and Definition of Find definitions for: un•suc•cess Pronunciation: (un"suk-ses'), [key] — n. lack of success; failure. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. unsubstantiated unsuccessful Related Content Daily Word Quiz: fabricate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language