supercharger definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
an engine-driven compressor used in some motor vehicles and airplanes to improve power by increasing the flow of air and fuel into the cylinders: also used in airplanes to pressurize cabins and to maintain adequate air pressure in the engine at higher altitudes
supercharger definition by American Heritage Dictionary
A blower or compressor, usually driven by the engine, for supplying air under high pressure to the cylinders of an internal-combustion engine.