/ Dictionary / Index P probable cause: Meaning and Definition of Find definitions for: prob'able cause' Pronunciation: [key] — Law. Law. reasonable ground for a belief, as, in a criminal case, that the accused was guilty of the crime, or, in a civil case, that grounds for the action existed: used esp. as a defense to an action for malicious prosecution. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. probable probable error Related Content Daily Word Quiz: immense Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language