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. 1-1.5 cm. convex-camp. sulcate, dark brown then blue-grey, powdered with white meal, deformed umbo obtuse; g. adnexed, whitish; s. 3-4 cm. slender, glabrous, blackish-blue; sp.

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

From European Fungus Flora: Agaricaceae by Massee, George

P. tough, exp. subfibrillose, umbo evanescent, greyish white, shining, floccosely scaly; g. shining white then dingy; s. long, striate, abruptly rooting. platyphylla, Fr.

From European Fungus Flora: Agaricaceae by Massee, George

P. 2-4 cm. conical, exp. rufous bay, prominent umbo darker; g. adnexed; s. 3-5 cm. equal, somewhat curved, violet above; sp. ——. var. argyropus.

From European Fungus Flora: Agaricaceae by Massee, George