umbo

IPA: ˈʌmboʊ

(historical) The boss of a shield, at or near the middle and usually projecting, sometimes in a sharp spike.
(biology) A boss, or rounded elevation, or a corresponding depression, in a palate, disk, or membrane.
(anatomy) An inward projection of the tympanic membrane of the ear.
(zoology) One of the lateral prominences just above the hinge of a bivalve shell.
(mycology) A bump or protrusion on the cap of a mushroom or toadstool.

Examples of "umbo" in Sentences

For example, these bivalve shells, probably arks Arcidae, each had a hole thru its umbo.
The above magnified picture was taken from below the varix; the umbo was towards the top.
For example, these bivalve shells, probably arks (Arcidae), each had a hole thru its umbo.
Running upward and slightly forward from the umbo is a reddish-yellow streak produced by the manubrium of the malleus.
Their coverings having now been removed, on each shield a carving of the head of Caesar could be seen on the umbo, or central knob.
The Romans called the point at which the cord connecting the fetus with the placenta was cut and tied off the umbilicus, from umbo, “knob, projection.”