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

Nouns

• umbones
  plural
• umbos
  plural

Etymology

Origin of umbo

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

Example Sentences

See Examples For:

umbo umbones umbos

P. 2-3 cm. exp. subdepressed round small umbo, pallid; g. free; s. 3-5 cm. glabrous, pallid, apex thickened; sp. ——. esculenta, Wulf.

From European Fungus Flora: Agaricaceae by George Massee

P. ovate then exp. reddish then greyish white, umbo rather fleshy, pellucidly striate at edge; g. decur.; s. yellowish brown, base floccosely rooting. rubida, Berk.

From European Fungus Flora: Agaricaceae by George Massee

P. 1-1.5 cm. exp. disc depr. round pale small umbo, rufous or yellowish; g. crowded, white; s. 3-5 cm. slender, tough, glabrous, tinged fuscous, base rooting, fibrillose; sp.

From European Fungus Flora: Agaricaceae by George Massee

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

From European Fungus Flora: Agaricaceae by George Massee

Differs from I. geophylla in dark umbo and rough sp.

From European Fungus Flora: Agaricaceae by George Massee

Valves 5, approximate; scuta with their umbones in the middle of the occludent margin; carina rectangularly bent, extending up between the terga, with the basal end simply concave.

From A Monograph on the Sub-class Cirripedia With Figures of all the Species. by Charles Darwin

Valves 2 to 5, minute, remote from each other: scuta with two or three lobes, with their umbones in the middle of the occludent margin: carina arched, upper and lower ends nearly alike.

From A Monograph on the Sub-class Cirripedia With Figures of all the Species. by Charles Darwin

The valves are plainly marked by the zones of successive growth; and most of them are ribbed and furrowed slightly, from their umbones to their basal margins.

From A Monograph on the Sub-class Cirripedia With Figures of all the Species. by Charles Darwin

The valves, excepting sometimes their umbones, are also covered with membrane, bearing spines, placed in rows parallel to the lines of growth; the spines are particularly numerous round the orifice of the sack.

From A Monograph on the Sub-class Cirripedia With Figures of all the Species. by Charles Darwin

The young Brachiopod in all its species is protected by an embryonic shell called the “protegulum,” which sometimes persists in the umbones of the adult shells but is more usually worn off.

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

A true terminal umbo rests on the surface of the underlying scale, although several species with terminal umbos show the first stages of the dorsal umbo.

From The Genus Pinus by George Russell Shaw