n. - One who, or that which, imparts motion; a source of mechanical power.
n. - A prime mover; a machine by means of which a source of power, as steam, moving water, electricity, etc., is made available for doing mechanical work.
n. - Alt. of Motorial
- A type of internal-combustion engine in which the air drawn in by the suction stroke is so highly compressed that the heat generated ignites the fuel (usually crude oil), the fuel being automatically sprayed into the cylinder under pressure. The Diesel engine has a very high thermal efficiency.
n. - A motor car; an automobile.