/ Dictionary / Index R root canal: Meaning and Definition of Find definitions for: root' canal" Pronunciation: [key] — Dentistry. Dentistry. Also calledthe root portion of the pulp cavity. See(def. 2). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. root beer root canal therapy Related Content Daily Word Quiz: clairvoyant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language