Umbo
n. pl. L. Umbones (#), E. Umbos (#).- The boss of a shield, at or near the middle, and usually projecting, sometimes in a sharp spike.
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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 - (Zoöl.) One of the lateral prominences just above the hinge of a bivalve shell.
