/ Dictionary / Index R rotary engine: Meaning and Definition of Find definitions for: ro'tary en'gine Pronunciation: [key] an engine, as a turbine, in which the impelling fluid produces torque directly rather than by acting upon reciprocating parts. a revolving radial engine. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. rotary dial rotary hoe Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language