/ Dictionary / Index O outboard motor: Meaning and Definition of Find definitions for: out'board mo'tor Pronunciation: [key] a portable gasoline engine with propeller and tiller, clamped on the stern of a boat. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. outboard outboard profile Related Content Daily Word Quiz: morose Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language