pl. um·bo′nes or um′bos
- the boss, or knob, at the center of a shield
- something resembling this; specif.,
- the elevation beside the hinge on each half of a bivalve shell
- the prominence on the eardrum at the point of attachment of the malleus
Origin of umboL, akin to umbilicus, navel
nounpl. um·bo·nes or um·bos
- The boss or knob at the center of a shield.
- a. Biology A knoblike protuberance arising from a surface, as the prominence near the hinge of a bivalve shell or the raised area in the center of the cap of a mushroom.b. Anatomy A small projection at the center of the outer surface of the eardrum.
Origin of umboLatin umb&omacron;, umb&omacron;n-; see nobh- in Indo-European roots.
(plural umbones or umbos or umboes)
- (biology) A boss, or rounded elevation, or a corresponding depression, in a palate, disk, or membrane; as, the umbo in the integument of the larvÃ¦ of echinoderms or in the tympanic membrane of the ear.
- (zoology) One of the lateral prominence just above the hinge of a bivalve shell.
- (mycology) A bump or protrusion on the top of the cap.
- (historical) The boss of a shield, at or near the middle, and usually projecting, sometimes in a sharp spike.
Borrowed from Latin umbo