Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio.
a person who has power and influence, esp. one who operates unofficially or behind the scenes as an intermediary
also written powerbroker
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.
A person who exerts strong political or economic influence, especially by virtue of the individuals and votes he or she controls.