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umbo

[ uhm-boh ]
/ ˈʌm boʊ /
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noun, plural um·bo·nes [uhm-boh-neez], /ʌmˈboʊ niz/, um·bos.
a boss on a shield, as one at the center of a circular shield.
any similar boss or protuberance.
Zoology. the beak of a bivalve shell; the protuberance of each valve above the hinge.
Anatomy. the depressed area on the outer surface of the tympanic membrane.
a blunt or rounded protuberance arising from a surface, as on a pine cone scale.
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Origin of umbo

1715–25; <Latin umbō boss (of a shield), knob, projecting part; akin to umbilīcus (see umbilicus)
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use umbo in a sentence

British Dictionary definitions for umbo

umbo
/ (ˈʌmbəʊ) /

noun plural umbones (ʌmˈbəʊniːz) or umbos
a small hump projecting from the centre of the cap in certain mushrooms
a hooked prominence occurring at the apex of each half of the shell of a bivalve mollusc
anatomy the slightly convex area at the centre of the outer surface of the eardrum, where the malleus is attached on the internal surface
a large projecting central boss on a shield, esp on a Saxon shield

Derived forms of umbo

umbonate (ˈʌmbənɪt, -ˌneɪt), umbonal (ˈʌmbənəl) or umbonic (ʌmˈbɒnɪk), adjective

Word Origin for umbo

C18: from Latin: boss of a shield, projecting piece
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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