UMBO

umbo. Umbo, n. the point or top of a buckler, a buckler

---

‖Um″bo (?), n.; pl. L. Umbones (#), E. Umbos (#). [] 1. 1. The boss of a shield, at or near the middle, and usually projecting, sometimes in a sharp spike.
2. 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. 3. (Zoöl.) One of the lateral prominences just above the hinge of a bivalve shell.