Category:Umbo

Um"bo, n.; pl. L. Umbones, e. Umbos. Etym: [l.]

1. The boss of a shield, at or near the middle, and usually Projecting, sometimes in a sharp spike.

2. A boss, or rounded elevation, or a corresponding depression, in a Palate, disk, or membrane; as, the umbo in the integument of the Larvæ of echinoderms or in the tympanic membrane of the ear.

3. (zoöl.)

Defn: one of the lateral prominence just above the hinge of a bivalve Shell.