/ Dictionary / Index D dement: Meaning and Definition of Find definitions for: de•ment Pronunciation: (di-ment'), [key] — v.t. Obs. to make mad or insane. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. demeclocycline demented Related Content Daily Word Quiz: impetuous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language