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  

/ ˈʌmbəʊ /

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

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Etymology

Origin of umbo

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

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Example Sentences

See Examples For:

umbo umbones umbos

P. 4-6 cm., umbo very strong, ochraceous, scaly; g. white; s. 9-15 cm. slender, base swollen, ring free; sp.

From European Fungus Flora: Agaricaceae by George Massee

P. convex, even, umbo fleshy, bay, shining; g. adnate, ovate, distant; s. solid, firm, wavy, naked, colour of p.; sp.

From European Fungus Flora: Agaricaceae by George Massee

P. striate, grey, umbo darker; g. greyish white; s. white, pruinose, base brownish, strigosely rooting; sp. globose, aculeate. vitilis, Fr.

From European Fungus Flora: Agaricaceae by George Massee

P. conico-campan. acute umbo blackish, rest reddish brown, striate; g. almost free, pale rose; s. cylindrical, almost translucent, brown, curved. carpophila, Fr.

From European Fungus Flora: Agaricaceae by George Massee

P. convex, depr. round broad umbo, maroon-bay then paler; g. narrow, adnato-decur. connected by numerous veins; s. tinged brown, squamulose, ring persistent, whitish. sphaleromorpha, Bull.

From European Fungus Flora: Agaricaceae by George Massee

Valves 5, approximate: carina extending up between the terga, terminating downwards in an embedded fork, or in an external disc: scuta sub-triangular, with their umbones at the rostral angle.

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

Scuta nearly oval, with their umbones at the rostral angle.

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

In the entire animal the posterior end projects slightly more than the anterior from the region of the umbones.

From Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 6 "Cockaigne" to "Columbus, Christopher" by Various

The umbones of the rostral latera must have been close together, over the unknown rostrum.

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

Shell longitudinal, wedge-shaped, equivalve, the valves gaping; the umbones straight, pointed.

From Zoological Illustrations, Volume III or Original Figures and Descriptions of New, Rare, or Interesting Animals by William Swainson

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

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