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

Brachiopoda, with the pedicle-opening, confined in later life to the ventral valve, and placed at the umbo or beneath it.

From Encyclopaedia Britannica, 11th Edition, Volume 4, Slice 3 "Borgia, Lucrezia" to "Bradford, John" by Various

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. obconic, umbo hemispher. prominent, at first hoarily silky then glabrous, dusky umber then pale; g. deeply decur.; s. flexile. atrorufa, Schaeff.

From European Fungus Flora: Agaricaceae by Massee, George

P. exp. depr. round umbo, even, glabrous, moist, edge spreading, even, whitish when dry; g. closely crowded, greyish. putidum, Fr.

From European Fungus Flora: Agaricaceae by Massee, George

P. 2-5 cm. conic camp. exp. striate up to umbo, dry, brownish, livid, &c.; adnate with decurrent tooth, connected by veins, pinkish when old; s. 5-8 cm. polished, even, glabrous; sp. 6-7 � 4.

From European Fungus Flora: Agaricaceae by Massee, George