valve

American  

[valv] / vælv /

noun

• valves
  plural

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.

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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 British  

/ 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

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valve Scientific  

/ vălv /

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

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Other Word Forms

Derived Forms

• undervalve
  noun
• valveless
  adjective
• valvelike
  adjective

Inflected Forms

Nouns

• valves
  plural

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Etymology

Origin of valve

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

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Explanation

A valve is a device that controls the flow of a liquid or gas. Before you fix the broken sink in your bathroom, you should turn the valve that shuts off the water. The simplest type of valve has a hinged flap allowing liquid to flow one direction, but blocking it from going the other way. This is called a "check valve." Anatomical valves — systems in your body that allow a flow of fluid, like the aortic valve near your heart — are structured very much the same way. The shells of mollusks like oysters and clams are also called valves. The word's earliest meaning was "one half of a folding door."

Example Sentences

See Examples For:

valve valves valved valving

Steam accumulator: Stores pressurized steam before release to the launch valve.

From The Wall Street Journal ● Oct. 12, 2026

Gas continued to leak from the ship for 12 minutes before the crew realised what was happening and were able to close the valve manually.

From BBC ● Oct. 9, 2026

In January 2025, they found methane gushing from the valve on a well.

From Los Angeles Times ● Oct. 3, 2026

The launch was originally planned for mid-September, but was delayed to replace a valve in the Crew Dragon's propulsion system.

From BBC ● Oct. 1, 2026

It keeps talking, like a boat motor with no shut-off valve, saying more stuff I want him to know, even though most of me knows he doesn’t care.

From "Red Flags and Butterflies" by Sheryl Azzam

As many of the valves are concealed within the building, substantial sections of the ceiling will have to be removed to gain access, according to engineers in the document seen by the BBC.

From BBC ● Nov. 4, 2026

Newport Beach said crews were rebuilding berms, opening tide valves and running pumps.

From Los Angeles Times ● Oct. 10, 2026

As drivers ratchet up to Sport and Race modes on the manettino controller, the active exhaust valves allow more volume and breathy resonance.

From The Wall Street Journal ● Sep. 26, 2026

The captain credited the GasLog Salem crew with quickly shutting gas tank valves, helping contain the fire.

From Barron's ● Aug. 1, 2026

Once more through the plan: Use the manual valves to equalize the airlock.

From "The Martian" by Andy Weir

Those wanting the enhanced protection without the same discomfort could turn to valved N95s instead.

From Slate ● May 20, 2022

"It was flushed into the drainage system that leads to an oil water separator that is valved off from the detention basin," Mura said.

From Salon ● Mar. 23, 2022

He immediately switched from the baritone horn, a valved instrument, to trombone.

From Washington Post ● May 11, 2021

Mr. Sax patented his family of valved brass instruments in 1846, as militarism was sweeping Europe.

From New York Times ● Nov. 6, 2015

He stood up, still chewing, put on his hieb, coat, and boots, and slipped otterlike out the self-sealing valved door.

From "The Left Hand of Darkness" by Ursula K. Le Guin

The secondary piston valving was then stiffened to make the shock more stable and progressive, as well as to give it more control later in the stroke.

From Time Magazine Archive

Finally Commander Lansdowne had to reconcile himself to "valving" the helium and allowing some 20,000 feet of the precious gas to escape at an estimated cost of $4,000.

From Time Magazine Archive

They first softened the primary piston, working a large amount on both the high and low speed compression valving in order to make the shock run a bit softer and have a much smoother action.

From Time Magazine Archive

They can have that type of data and information, and oil and spring rates and valving.

From Time Magazine Archive

Dean Moran, opposite, eyes clenched, lips valving open as a cobra slithers out, a shiny cobra of half-digested toffee apple, candy floss, and three of Fryer Tuck's All-American Taste-Tastic Hot Dogs, highly recommended, writhing longer.

From "Black Swan Green" by David Mitchell

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