signet ring

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

• noun A finger ring bearing an engraved signet.

from The Century Dictionary.

• noun A seal-ring the seal of which is a signet, or private seal.
• noun One of the forms of the malarial parasite in which the body is of a ring shape thickened on one side.

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

• noun A finger ring bearing a signet, seal or coat of arms

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

• noun a ring bearing a signet