Definition of umbo in English:
noun (plural umbones ʌmˈbəʊniːz or umbos)
2.1 Zoology The highest point of each valve of a bivalve shell.
- The new species is characterized by a transversely extended, strongly biconvex to globular shell with prominent umbones, relatively numerous costae and a notothyrial cavity supported dorsally by a short median ridge.
- Argonauta attaches the egg-mass to the umbo of the shell near the dorsal arms, not in the mantle cavity or posterior parts of the shell.
- Below the umbones, the shell margin is folded inward forming a deep lunula and gaping between both valves.
Early 18th century: from Latin, 'shield boss'.
umbonal adjective (chiefly Zoology )
- Example sentences
- Cyzicus having elongate valves; umbo convex; dorsal margin straight; posterior margin slightly flared; growth bands widely spaced in umbonal region, more closely spaced elsewhere.
- The umbonal angle narrows while the shape remains mytiliform and the ‘lunule’ (byssal invagination) remains shallow.
- Hinge articulation either limited to overlapping shell margins on dorsal side of byssal invagination or consisting of a transposable tooth and socket developed on the umbonal septum.
- Example sentences
- M. oreades has a white spore print, adnate, adnexed or even free gills usually white to pale tan in colour, a mid-sized bell-shaped cap but can later become umbonate as it ages.
- Other decorative British products of this period include ‘umbonate’ disc brooches.
- An umbonate colony is elevated more in the center of the colony than the rise across the surface of the colony.
Pronunciation: /ˈʌmbənət/adjective (chiefly Botany )
Words that rhyme with umboColombo, dumbo, gumbo, jumbo, mumbo-jumbo
Definition of umbo in:
- US English dictionary
What do you find interesting about this word or phrase?
Comments that don't adhere to our Community Guidelines may be moderated or removed.
Most popular in the US
Most popular in the UK
Most popular in Canada
Most popular in Australia
Most popular in Malaysia
Most popular in Pakistan