Generator \Gen"er*a`tor\, n. [L.] 1. One who, or that which, generates, begets, causes, or produces. 2. An apparatus in which vapor or gas is formed from a liquid or solid by means of heat or chemical process, as a steam boiler, gas retort, or vessel for generating carbonic acid gas, etc. 3. (Mus.) The principal sound or sounds by which others are produced; the fundamental note or root of the common chord; -- called also {generating tone}.