(noun, verb)


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

Definition categories: body, structure

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

Definition categories: man–made, device

3. control consisting of a mechanical device for controlling the flow of a fluid

Definition categories: man–made, control, controller

4. the entire one-piece shell of a snail and certain other molluscs

Definition categories: animal, shell

5. one of the paired hinged shells of certain molluscs and of brachiopods

Definition categories: animal, shell


1. (transitive) To control (flow) by means of a valve.