/ Dictionary / Index U underage: Meaning and Definition of Find definitions for: un•der•age Pronunciation: (un"dur-āj'), [key] — adj. lacking the required age, esp. that of legal maturity. un•der•age Pronunciation: (un'dur-ij), [key] — n. shortage; deficiency in amount. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: underage (Thesaurus) underactive underarm Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language