velum

views updated May 11 2018

ve·lum / ˈvēləm/ • n. (pl. ve·la / -lə/ ) a membrane or membranous structure, typically covering another structure or partly obscuring an opening, in particular: ∎  Anat. the soft palate. ∎  Zool. a membrane, typically bordering a cavity, esp. in certain mollusks, medusae, and other invertebrates. ∎  Bot. the veil of a toadstool.

velum

views updated May 14 2018

velum From the Latin velum, ‘ship's sail’. 1. In Mollusca, the ciliated lobe possessed by the veliger larva.2. In most hydroid medusae (Cnidaria), a ridge or narrow shelf inside the border of the sub-umbrellar (See UMBRELLAR) cavity which reduces the size of the subumbrellar aperture and so increases the force of the water jet by which the medusa swims vertically.

velum

views updated May 08 2018

velum An accessory cloud feature of cumulus or cumulonimbus, characterized by a widespread veil on or above the upper surface of the cloud. See also CLOUD CLASSIFICATION.

velum

views updated May 29 2018

velum An accessory cloud feature of cumulus or cumulonimbus, characterized by a widespread veil on or above the upper surface of the cloud. See also cloud classification.

velum

views updated Jun 27 2018

velum
1. A flap of membranous tissue that protects a sporangium in Isoetaceae.

2. In certain toadstools and mushrooms, the remains of the partial veil after it has ruptured.

velum

views updated May 14 2018

velum (anat.) soft palate XVIII; (zool., bot.) membranous structure XIX. — modL. use (in full v. palati, v. pendulum veil of the palate, pendulous veil) of L. vēlum (see VEIL).

VELUM

views updated Jun 11 2018

VELUM, also soft palate. The soft part of the roof of the mouth, behind the hard palate. There are two adjectives: velar, for the velum itself and sounds made by raising the back of the tongue towards the velum; velaric, referring to a stream of air. See ARTICULATION SPEECH.

velum

views updated Jun 08 2018

velum (pl. vela). Segment of the awning (velarium) of a Roman amphitheatre, etc.

velum

views updated May 21 2018

velum See annulus.