King's Counsel

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A barrister of the highest rank. Used when the sovereign is a man.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun In the United Kingdom, a barrister selected to serve as counsel for the British Crown. First used in 1689.
• noun In Canada, an honorific status conferred by the federal or provincial governments to senior or meritorious lawyers.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun Counsel to the Crown when the British monarch is a king