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.

---

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

---

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

From European Fungus Flora: Agaricaceae by Massee, George

S. 2-3 cm. long, wavy, peronate with white veil, cingulate, umbo blackish. punctatus, Fr.

From European Fungus Flora: Agaricaceae by Massee, George

P. whitish, umbo bluish-green; g. narrow, white then fuscous; stem white pruinose; sp.

From European Fungus Flora: Agaricaceae by Massee, George

P. 1.5-2.5 cm. camp. grey, umbo darker, striate to middle, margin upturned and splitting; g. adnexed, grey; s. 2.5-3.5 cm. dry, smooth, paler than p.; sp.

From European Fungus Flora: Agaricaceae by Massee, George

P. 4-7 cm. incurved then exp. glabrous, hygr. tawny-rusty then cracked umbo obtuse, vanishing; g. very broad, thick; s. 10-18 cm. attenuated, veil silky, almost smooth, peronate, terminated by a rusty edged annular zone; sp.

From European Fungus Flora: Agaricaceae by Massee, George