/ 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: abscond Analogy of the Day: Today?s Analogy Spelling Bee: Today?s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language