英汉词典

1. 阀;活门
    A valve is a device attached to a pipe or a tube which controls the flow of air or liquid through the pipe or tube.

2. （心脏的）瓣，瓣膜
    A valve is a small piece of tissue in your heart or in a vein which controls the flow of blood and keeps it flowing in one direction only.

    e.g. He also has problems with a heart valve.
           他的一个心瓣也有毛病。

3. see also: safety valve