I. ˈin-ˌbȯrd adverb
Date: 1830
1. : inside the line of a ship's bulwarks or hull
2. : toward the center line of a vehicle or craft (as a ship or aircraft)
II. adjective
Date: 1847
1. : located inboard
an inboard engine
an inboard spoiler
2. of a boat : having an inboard engine
III. noun
Date: 1939
: a boat with an inboard motor