/ Dictionary / Index E efficient cause: Meaning and Definition of Find definitions for: effi'cient cause' Pronunciation: [key] — Aristotelianism. Aristotelianism. See under(def. 8b). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. efficient Effie Related Content Daily Word Quiz: procrastinate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language