VELUM

‖Ve″lum (?), n.; pl. Vela (#). [[L., an awning, a veil. See Veil.]] 1. 1. (Anat.) A curtain or covering; — applied to various membranous partitions, especially to the soft palate. See under Palate.
2. 2. (Bot.) (a) See Veil, n., 3 (b). (b) A thin membrane surrounding the sporocarps of quillworts Isoetes).
3. 3. (Zoöl.) A veil-like organ or part. Especially: (a) The circular membrane that partially incloses the space beneath the umbrella of hydroid medusæ. (b) A delicate funnel-like membrane around the flagellum of certain Infusoria. See Illust. a of Protozoa.