minority leader

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

• noun The head of the minority party in a legislative body.

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

• noun US In each of the legislative chambers of the United States Congress—the United States Senate and the House of Representatives—the elected member selected by the members of the political party with the second-largest number of elected members, who serves as principal spokesperson for the members of that party in that chamber and who plays a leading role in creating policies and strategies governing his or her party's business in that chamber.

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

• noun leader of the minority party in a legislature