/ Dictionary / Index G grown-up: Meaning and Definition of Find definitions for: grown-up Pronunciation: (grōn'up'), [key] — adj. having reached the age of maturity. characteristic of or suitable for adults: grown-up behavior; grown-up fiction. grown•up Pronunciation: (grōn'up"), [key] — n. a mature, fully grown person; adult. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: grown-up (Thesaurus) grown growth Related Content Daily Word Quiz: neologism Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language