/in"bawrd'owt"bawrd', in"bohrd'owt"bohrd'/ , adj.
1. Also, outdrive, stern-drive . (of a motorboat) having an inboard engine connected to a maneuverable outboard drive-shaft unit.
n.
2. an inboard-outboard motor.
3. a boat equipped with such a motor. Abbr.: I/O Also called outdrive, stern drive (for defs. 2, 3).