(redirected from umbones)
Also found in: Dictionary, Thesaurus, Medical.


A rounded elevation of the surface of the tympanic membrane.
(invertebrate zoology)
A prominence above the hinge of a bivalve mollusk shell.



the iron central boss of a shield, which protected the warrior’s hand. Under the hemispherical or conical umbo was a crosspiece by which the shield was held. Shields with umbones were widely used in ancient Greece and Rome and in medieval Europe and Rus’.

References in periodicals archive ?
Umbones pequenos, centrales, muy juntos, que se continuan en una linea axial hasta el margen ventral, dividiendo la concha en dos partes muy similares.
valdensis (Mantell, 1844) housed in Natural History Museum of London show an identical heart-shape sculpture on the umbones (Fig.
capax larval shell is almost symmetrical in longitudinal profile and has low and knobby umbones.