n.
- a device for controlling the passage of fluid through a pipe or duct, especially an automatic device which allows movement in one direction only.
- a cylindrical mechanism to vary the effective length of the tube in a brass musical instrument.
- Anatomy & Zoology a membranous fold in an organ or vessel which allows blood or other fluid to flow in one direction.
- Zoology each of the halves of the hinged shell of a bivalve mollusc or brachiopod.
- Botany each of the halves or sections into which a dry fruit dehisces.
Derivative
- valved adj.
- valveless adj.
Etymology
ME (denoting a leaf of a folding or double door): from L. valva.