Velum n. : Curtain or covering; -- applied to various membranous partitions, especially to the soft palate. See under Palate.

Velum n. : See Veil, n., 3 (b).

Velum n. : A thin membrane surrounding the sporocarps of quillworts Isoetes).

Velum n. : A veil-like organ or part.

Velum n. : The circular membrane that partially incloses the space beneath the umbrella of hydroid medusae.

Velum n. : A delicate funnel-like membrane around the flagellum of certain Infusoria. See Illust. a of Protozoa.

Example:
What is the difference between cistern of Velum interpositum and the 3rd ventricle?

Taxonomy
superior medullary velum, free encyclopedia, veil, stem, delicate membrane, circular membrane, search, free dictionary, sail, curtain, awning, meanings, organ, class Hydrozoa, propulsion, membrane, mushroom, button mushrooms.

Defination from the web:
velum. a thin flap of tissue completely or partially covering the adaxial wall of the sporangium in species of Isoetes. Velum is also a common misspelling of vellum, calfskin (or sometimes the skins of other animals) that is similar to parchment and that is used as ...