umbo

American  

[uhm-boh] / ˈʌm boʊ /

noun

plural

umbones, umbos

1. a boss on a shield, as one at the center of a circular shield.

2. any similar boss or protuberance.

3. Zoology. the beak of a bivalve shell; the protuberance of each valve above the hinge.

4. Anatomy. the depressed area on the outer surface of the tympanic membrane.

5. a blunt or rounded protuberance arising from a surface, as on a pine cone scale.

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umbo British  

/ ˈʌmbənɪt, ʌmˈbɒnɪk, -ˌneɪt, ˈʌmbəʊ, ˈʌmbənəl /

noun

1. a small hump projecting from the centre of the cap in certain mushrooms

2. a hooked prominence occurring at the apex of each half of the shell of a bivalve mollusc

3. anatomy the slightly convex area at the centre of the outer surface of the eardrum, where the malleus is attached on the internal surface

4. a large projecting central boss on a shield, esp on a Saxon shield

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Other Word Forms

• umbonate adjective

Etymology

Origin of umbo

1715–25; < Latin umbō boss (of a shield), knob, projecting part; akin to umbilīcus ( umbilicus )

Example Sentences

P. 3-4 cm. white, umbo brownish, striate to middle; g. decurrent; s. equal, hollow upwards, 4-5 cm., even up to torn ring, punctate above, white; sp.

From European Fungus Flora: Agaricaceae by Massee, George

P. 1.5-2 cm. camp.-convex, coarsely striate, hygr. broad obtuse umbo prominent, brownish; g. uncinate, thin, connected by veins; s. 4-5 cm. glabrous, shining subcompressed; sp. ——. stannea, Fr.

From European Fungus Flora: Agaricaceae by Massee, George

P. exp. dry, tan, umbo darker; g. quite free, closely crowded; s. slender, equal, white, ring torn.

From European Fungus Flora: Agaricaceae by Massee, George

P. convex, subdepr. with a slight umbo, whitish yellow; g. crowded, pale cinnamon; s. reddish. macilenta, Fr.

From European Fungus Flora: Agaricaceae by Massee, George

The hand was protected by a hollow conical boss or umbo, fixed to the wood by its brim, but projecting considerably.

From Beowulf An Introduction to the Study of the Poem with a Discussion of the Stories of Offa and Finn by Chambers, R. W.