bun

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

• noun An unsweetened round or oblong roll, used especially to hold a hamburger patty or a hot dog.
• noun A small sweetened roll, often spiced or containing dried fruit.
• noun A tight roll of hair worn at the back of the head.
• noun A drunken spree.

from The Century Dictionary.

• noun A slightly sweetened and flavored roll or biscuit; a sweet kind of bread baked in small cakes, generally round.
• noun A dry stalk; the dry stalk of hemp stripped of its rind.
• noun The tail of a hare.
• noun A rabbit. Also called bunny.
• noun A flat-bottomed boat square at both ends.

from the GNU version of the Collaborative International Dictionary of English.

• noun any of a variety of slightly sweetened or plain raised cakes or bisquits, often having a glazing of sugar and milk on the top crust.
• noun a type of coiffure in which the hair is gathered into a coil or knot at the top of the head.
• noun slang the buttocks.
• noun (Med.) same as blood urea nitrogen; the concentration of nitrogen in blood present in the form of urea; -- used as a measure of kidney function.

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

• noun A small bread roll, often sweetened or spiced.
• noun A tight roll of hair worn at the back of the head.
• noun slang, UK A drunken spree.
• noun Internet, slang A newbie.
• noun dialect, obsolete A squirrel or rabbit.
• verb UK, slang To smoke cannabis.

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

• noun small rounded bread either plain or sweet