What is Valve?

Valve definition and meaning on Dictionary terms:
any device for halting or controlling the flow of a liquid, gas, or other material through a passage, pipe, inlet, outlet, etc.
a hinged lid or other movable part that closes or modifies the passage in such a device.
Anatomy. a membranous fold or other structure that controls the flow of a fluid, as one that permits blood to flow in one direction only.
(in musical wind instruments of the trumpet class) a device for changing the length of the air column to alter the pitch of a tone.
Zoology. one of the two or more separable pieces composing certain shells.either half of the silicified shell of a diatom.

Botany. one of the segments into which a capsule dehisces.a flap or lidlike part of certain anthers.

Electronics (chiefly British ). vacuum tube(def 1).
Archaic. one of the leaves of a double or folding door.

verb (used with object), valved, valv