/ Dictionary / Index B borderline personality: Meaning and Definition of Find definitions for: bor'derline personal'ity Pronunciation: [key] a personality disorder characterized by instability in many areas, as mood, identity, self-image, and behavior, and often manifested by impulsive actions, suicide attempts, inappropriate anger, or depression. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. border line Borders Related Content Daily Word Quiz: paradox Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language