/ Dictionary / Index D developmentalist: Meaning and Definition of Find definitions for: de•vel•op•men•tal•ist Pronunciation: (di-vel"up-men'tl-ist), [key] — n. an expert in or advocate of developmental psychology. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. developmental disability developmental psychology Related Content Daily Word Quiz: censure Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language