Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio.
a substance, usually a fluid, used to remove heat, as from a nuclear reactor, an internal-combustion engine, molten metal, etc.
Used by arrangement with John Wiley & Sons, Inc.
The American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
An agent that produces cooling, especially a fluid that draws off heat by circulating through an engine or by bathing a mechanical part.