noun.
A usually propeller-driven vehicle designed for traveling over land or water by riding on a layer pressurized air forced downward from the vehicle's bottom.
the GNU version of the Collaborative International Dictionary of English
noun.
A vehicle that rides over water or land supported by the pressure of a stream of air generated by downward-thrusting fans, and is propelled forward by an air propeller; also called ACV and air-cushioned vehicle.