Velum

Definition:

(n.) Curtain or covering; -- applied to various membranous partitions, especially to the soft palate. See under Palate.
(n.) See Veil, n., 3 (b).
(n.) A thin membrane surrounding the sporocarps of quillworts Isoetes).
(n.) A veil-like organ or part.
(n.) The circular membrane that partially incloses the space beneath the umbrella of hydroid medusae.
(n.) A delicate funnel-like membrane around the flagellum of certain Infusoria. See Illust. a of Protozoa.

Compare velum with other words:

vellum vs. velum