medallion

Short definition from Wiktionary

Noun

1. 1
   A large medal, usually decorative.
2. 2
   A cut of meat resembling a large medal.
3. 3
   A usually round or oval frame (often made of stucco) containing a decoration.
4. 4
   A circular certificate used in some places to register a vehicle, especially a taxicab.
5. 5
   A yellowish brown.

Verb

1. 1
   To mark with, or as with, a medallion or medallions.