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

Etymology

Origin of valve

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

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

Transcatheter aortic valve replacement sales, which make up the bulk of Edwards Lifesciences’ top line, rose 11% to $1.26 billion.

From The Wall Street Journal ● Jul. 23, 2026

The recent correction has served as a necessary relief valve, reducing the risk of a blow-off top while allowing leadership to broaden.

From MarketWatch ● Jul. 22, 2026

Turning the valve back on gets oil moving, but it takes time to optimize the tanker/refiner matching.

From MarketWatch ● Jul. 21, 2026

Nightclubbing started some 350 years ago in Yoshiwara, near Tokyo, “a flashy pleasure quarter” of feudal Japan that served, Ms. Willetts writes, as “the ultimate pressure valve for the shogun’s otherwise disciplined regime.”

From The Wall Street Journal ● Jul. 17, 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

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

From Barron's ● Aug. 1, 2026

"We were surprised by how much P. gingivalis was present in the calcified aortic valves," Li said.

From Science Daily ● Jul. 13, 2026

A year earlier, suspected Russian hackers remotely manipulated valves on a Norwegian hydroelectric dam.

From The Wall Street Journal ● Jul. 4, 2026

That means parents will have few relief valves to make the payments manageable.

From MarketWatch ● Jul. 1, 2026

Then Uncle Hermilio asked Lucky about his car, and Lucky started talking about valves and piston rings and carburetors.

From "Lupita Mañana" by Patricia Beatty

Still today, the World Health Organization advises against using valved N95s.

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

No, we have valving scenarios that are designed to handle any rider and any bike out there, bar none.

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

If he happens to lose it, he can, according to Diver Nohl, rise of his own accord by valving gas into the suit.

From Time Magazine Archive

The biggest changes are new, softer dual-rate springs and revised 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

Related Words

• faucet
• pipe
• spigot