inboard-outboard in American English
(ˈinˌbɔrdˈautˌbɔrd, ˈinˌbourdˈautˌbourd)
adjective1. Also: outdrive, stern-drive (of a motorboat) having an inboard engine connected to a maneuverable outboard drive-shaft unit
noun2. an inboard-outboard motor
3. a boat equipped with such a motor
Abbreviation: I/O. Also called (for defs. 2, 3): outdrive, stern drive