/ Dictionary / Index I interpersonal theory: Meaning and Definition of Find definitions for: interper'sonal the"ory Pronunciation: [key] — Psychol. Psychol. the theory that personality development and behavior disorders are related to and determined by relationships between persons. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. interpersonal interpersonal therapy Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language