/ Dictionary / Index I immature: Meaning and Definition of Find definitions for: im•ma•ture Pronunciation: (im'u-choor', -toor', -tyoor', -chûr'), [key] — adj. not mature, ripe, developed, perfected, etc. emotionally undeveloped; juvenile; childish. youthful (def. 5). premature. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: immature (Thesaurus) immaterialize immaturity Related Content Daily Word Quiz: sequester Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language