1.Definition: a structure in a hollow organ (like the heart) with a flap to insure one-way flow of fluid through it

Category: General

2.Definition: control consisting of a mechanical device for controlling the flow of a fluid

Category: Objects

3.Definition: device in a brass wind instrument for varying the length of the air column to alter the pitch of a tone

Category: Objects

4.Definition: one of the paired hinged shells of certain molluscs and of brachiopods

Category: Animals

5.Definition: the entire one-piece shell of a snail and certain other molluscs

Category: Animals