/ Dictionary / Index E exclusionary rule: Meaning and Definition of Find definitions for: exclu'sionary rule" Pronunciation: [key] a rule that forbids the introduction of illegally obtained evidence in a criminal trial. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. exclusion exclusion clause Related Content Daily Word Quiz: heifer Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language