/ Dictionary / Index I infantilize: Meaning and Definition of Find definitions for: in•fan•til•ize Pronunciation: (in'fun-tl-īz", -tī-līz", in-fan'tl-īz"), [key] — -ized, -iz•ing. to keep in or reduce to an infantile state. to treat or regard as infantile or immature. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. infantilism infantine Related Content Daily Word Quiz: banshee Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language