/ Dictionary / Index R radial engine: Meaning and Definition of Find definitions for: ra'dial en'gine Pronunciation: [key] — Aeron. Aeron. an internal-combustion engine having the cylinders arranged in radial opposition, found mainly on older aircraft. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. radial radial keratotomy Related Content Daily Word Quiz: modify Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language