/ Dictionary / Index P personality disorder: Meaning and Definition of Find definitions for: personal'ity disor"der Pronunciation: [key] — Psychiatry. Psychiatry. any of a group of mental disorders characterized by deeply ingrained maladaptive patterns of behavior and personality style, which are usually recognizable as early as adolescence and are often lifelong in duration. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. personality personality inventory Related Content Daily Word Quiz: deleterious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language