/ Dictionary / Index U underachieve: Meaning and Definition of Find definitions for: un•der•a•chieve Pronunciation: (un"dur-u-chēv'), [key] — -a•chieved, -a•chiev•ing. to perform, esp. academically, below the potential indicated by tests of one's mental ability or aptitude. to perform below expectations or achieve less than expected, esp. by others. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: underachieve (Thesaurus) under underachiever 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