umbo

American  

[uhm-boh] / ˈʌm boʊ /

noun

umbones, plural umbos plural

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

Derived Forms

• umbonate
  adjective

Inflected Forms

noun

• umbos
  plural
• umbones
  plural

Etymology

Origin of umbo

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

Example Sentences

P. 1-2 cm. campan.-convex subumb. glabrous, pellucidly striate from umbo when moist, rusty yellow then pale, edge almost straight; g. adnate, ventricose; s. 4-7 cm. rusty, with white fibrillose squamules up to middle; sp.

From European Fungus Flora: Agaricaceae by Massee, George

P. 2-3 cm. soon depr. round conical umbo, smoky grey, somewhat streaked; g. crowded, adnexed, narrow, white then greyish; s. 2-3 cm. dingy grey, slightly striate base thickened; sp. 10-11 � 5-6.

From European Fungus Flora: Agaricaceae by Massee, George

Pileus submembranaceous, conical then exp. umbo acute, rarely obtuse or nearly obsolete, edge at first straight.

From European Fungus Flora: Agaricaceae by Massee, George

P. 5-7 cm. convex then exp. depressed round the umbo, blackish umber, even, glabrous; g. reddish cinnamon; s. 4-6 cm. hollow, somewhat twisted, fibrillose, greyish fuscous; sp. subgl. rough, 8 � 9.

From European Fungus Flora: Agaricaceae by Massee, George

L. prominens differs in very large umbo and permanent, free ring. mastoidea, Fr.

From European Fungus Flora: Agaricaceae by Massee, George