valve

[valv]

noun

1. any device for halting or controlling the flow of a liquid, gas, or other material through a passage, pipe, inlet, outlet, etc.

2. a hinged lid or other movable part that closes or modifies the passage in such a device.

3. 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.

4. (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.

5. Zoology.

   1. one of the two or more separable pieces composing certain shells.

   2. either half of the silicified shell of a diatom.

6. Botany.

   1. one of the segments into which a capsule dehisces.

   2. a flap or lidlike part of certain anthers.

7. Electronics (chiefly British).,  vacuum tube.

8. Archaic.,  one of the leaves of a double or folding door.

verb (used with object)

valved, valving 

1. to provide with a means of controlling the flow of liquid, gas, etc., by inserting a valve.

valve

/ vælv /

noun

1. any device that shuts off, starts, regulates, or controls the flow of a fluid

2. anatomy a flaplike structure in a hollow organ, such as the heart, that controls the one-way passage of fluid through that organ

3. Also called: tube.  vacuum tube. an evacuated electron tube containing a cathode, anode, and, usually, one or more additional control electrodes. When a positive potential is applied to the anode, electrons emitted from the cathode are attracted to the anode, constituting a flow of current which can be controlled by a voltage applied to the grid to produce amplification, oscillation, etc See also diode triode tetrode pentode

4. zoology any of the separable pieces that make up the shell of a mollusc

5. music a device on some brass instruments by which the effective length of the tube may be varied to enable a chromatic scale to be produced

6. botany

   1. any of the several parts that make up a dry dehiscent fruit, esp a capsule

   2. either of the two halves of a diatom cell wall

7. archaic,  a leaf of a double door or of a folding door

valve

1. 1. Any of various mechanical devices that control the flow of liquids, gases, or loose material through pipes or channels by blocking and uncovering openings.

   2. The movable part or element of such a device.

2. Any of various structures that prevent the backward flow of a body fluid, such as blood or lymph. Valves in the heart, veins, and lymphatic vessels contain flaps (known as cusps) that close in response to pressure created by the backflow of fluid.

3. One of the paired hinged shells of certain mollusks, such as clams and oysters.

4. See electron tube

Other Word Forms

• valveless adjective
• valvelike adjective
• undervalve noun

Word History and Origins

Origin of valve¹

1350–1400; Middle English < Latin valvae leaves of a door

Word History and Origins

Origin of valve¹

C14: from Latin valva a folding door

Example Sentences

It is moving into other areas of cardiovascular disease, such as mitral valve replacement and tricuspid valve replacement.

Read more on Barron's

The Fire Department trains to isolate and extinguish these types of fires by “controlling the valves that can restrict the flow” of the fuel, Snow said.

Read more on Los Angeles Times

In that incident, the board’s investigation found multiple safety failures, including a severely eroded safety valve that allowed flammable gases to dangerously seep into unwanted areas.

Read more on Los Angeles Times

The surgery was approved by the hospital solely for use in children and young adults, the BBC understands, though Ms Booth had permission to offer the procedure for patients with aortic valve disease.

Read more on BBC

"I would say that this is an attempt to give young people a valve to let off steam - so that they can at least have the illusion of a quick trip abroad," he says.

Read more on BBC

Related Words

• faucet 
• pipe 
• spigot