Main Entry:

um·bo

Pronunciation:

\ˈəm-(ˌ)bō\

Function:

noun

Inflected Form(s):

plural um·bo·nes \ˌəm-ˈbō-(ˌ)nēz\ or umbos

Etymology:

Latin; akin to Latin umbilicus — more at navel

Date:

1721

1: the boss of a shield2: a rounded elevation: as a: an inward projection of the tympanic membrane of the ear b: one of the lateral prominences just above the hinge of a bivalve shell

— um·bo·nal \ˈəm-bə-n^əl, ˌəm-ˈbō-\ adjective

— um·bo·nate \ˈəm-bə-ˌnāt, ˌəm-ˈbō-nət\ adjective

[umbo illustration]