- (n.) A boss or rounded elevation or a corresponding depression, in a palate, disk or membrane; as, the umbo in the integument of the larvae of echinoderms or in the tympanic membrane of the ear.
- (n.) The boss of a shield, at or near the middle, and usually projecting, sometimes in a sharp spike.
- (n.) One of the lateral prominence just above the hinge of a bivalve shell.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). umbo. Retrieved September 20, 2026, from http://smartdefine.org/umbo/definitions/2076122 |
| Chicago | Webster's. 2011. "umbo" http://smartdefine.org/umbo/definitions/2076122 (accessed September 20, 2026). |
| Harvard | Webster's 2011, umbo, Smart Define, viewed 20 September, 2026, <http://smartdefine.org/umbo/definitions/2076122>. |
| MLA | Webster's. "umbo" 28 May 2011. Web. 20 September 2026. <http://smartdefine.org/umbo/definitions/2076122> |