valve (Noun) — A structure in a hollow organ (like the heart) with a flap to insure one-way flow of fluid through it.
valve (Noun) — Device in a brass wind instrument for varying the length of the air column to alter the pitch of a tone.
valve (Noun) — Control consisting of a mechanical device for controlling the flow of a fluid.
valve (Noun) — The entire one-piece shell of a snail and certain other molluscs.
valve (Noun) — One of the paired hinged shells of certain molluscs and of brachiopods.
valve (Verb) — To control (flow) by means of a valve.