/ Dictionary / Index R reciprocating engine: Meaning and Definition of Find definitions for: recip'rocating en"gine Pronunciation: [key] any engine employing the rectilinear motion of one or more pistons in cylinders. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. reciprocate reciprocation Related Content Daily Word Quiz: placid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language