Velum

Part of speech: noun (n.)

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

2. See Veil, n., 3 (b).

3. A thin membrane surrounding the sporocarps of quillworts Isoetes).

4. A veil-like organ or part. Especially:

5. The circular membrane that partially incloses the space beneath the umbrella of hydroid medusæ.

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