n.[c]

1. 【机】阀，活门
   The exhaust valve on my car has burnt out three times.

   我车子上的排气阀已烧坏三次。

2. 【解】瓣，瓣膜
   The valves of the heart allow the blood to pass in one direction only.

   心脏的瓣膜使血液只能朝一个方向流动。

3. 【英】真空管
4. 贝壳
5. （管乐器的）活栓

vt.

1. 装阀于
2. 以活门调节

n.

1. a device for controlling the passage of fluid through a pipe or duct, especially an automatic device which allows movement in one direction only.
2. a cylindrical mechanism to vary the effective length of the tube in a brass musical instrument.
3. Anatomy  & Zoology  a membranous fold in an organ or vessel which allows blood or other fluid to flow in one direction.
4. Zoology  each of the halves of the hinged shell of a bivalve mollusc or brachiopod.
5. Botany  each of the halves or sections into which a dry fruit dehisces.