/ Dictionary / Index D derangement: Meaning and Definition of Find definitions for: de•range•ment Pronunciation: (di-rānj'munt), [key] — n. the act of deranging. insanity. disarrangement; disorder. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: derangement (Thesaurus) deranged deration Related Content Daily Word Quiz: agitated Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language