- outboard⇄adj., adv. 1. outside of the hull of a ship or boat.
2. away from the middle of a ship, boat, or aircraft.
3. outside of or away from the middle of an aircraft or spacecraft.
Ex. an outboard aerial.
4. (in machinery) outside; ou - outboard⇄noun 1. a small boat with an outboard motor.
2. outboard motor. - outboard⇄outboard, adjective, adverb, noun.