cowboy hat

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

• noun A hat having a tall usually creased crown and a very wide brim, often made of felt or straw and characteristically worn by cowboys and ranchers in the western United States.

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

• noun A broad-brimmed hat worn by cowboys, ranchers, and farmers, common in the western United States and Mexico.

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

• noun a hat with a wide brim and a soft crown; worn by American ranch hands