Any such watercraft.
A watercraft built like a motorcycle that is propelled by a jet of water.
A trademark for a personal watercraft.
A small motorized water craft with a flattish hull and an upright centre, which a rider sits astride.
2006: "Jet ski" is actually Kawasaki's name for their PWC (personal water craft) models, but like hoovers and speedos has become genericised. — Tracks magazine, Gimme Fuel: High Octane Advise for Buying a Ski, October 2006, page 154.