- inboard⇄adv., adj. 1. inside the hull of a ship or boat.
Ex. an inboard motor.
2. in or toward the middle of a ship or boat.
Ex. The cables were passed inboard through a block.
3. in or toward the center of an aircraft or spacecraft clos - inboard⇄inboard, adverb, adjective, noun.
- inboard⇄noun a boat containing an inboard motor.