medallion

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

• noun A large medal.
• noun An emblem of registration for a taxicab.
• noun Any of various large ancient Greek coins.
• noun Something resembling a large medal, as.
• noun An oval or circular design used as decoration.
• noun A painting or an engraving set in an oval or circular frame.
• noun A circular portion of food, especially a boneless cut of meat.

from The Century Dictionary.

• noun A medal of large size.
• noun Anything resembling the classical medallion.

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

• noun A large medal or memorial coin.
• noun A circular or oval (or, sometimes, square) tablet bearing a figure or figures represented in relief.

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

• noun A large medal, usually decorative.
• noun A cut of meat resembling a medallion.
• noun architecture A round or oval frame (often made of Stucco) which contains a plastic or pictorial decoration of a facade, an interior, a piece of furniture or equipment.
• noun A circular certificate used in some places to register a vehicle, especially a taxicab.

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

• noun a circular helping of food (especially a boneless cut of meat)
• noun any of various large ancient Greek coins
• noun an emblem indicating that a taxicab is registered
• noun an award for winning a championship or commemorating some other event