top hat definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
a tall, black, cylindrical hat, usually of silk, worn by men in formal dress
top hat definition by American Heritage Dictionary
A man's hat having a narrow brim and a tall cylindrical crown, usually made of silk. Also called high hat.