English Reference

Word

valve

US/ˈvæɫv/

UK/vˈælv/

Definitions

01mechanical device

B2 · Technical

n. a mechanical part in a pipe or machine that opens and closes to control the flow of water, gas, or air.

n. a mechanical device used to regulate the flow of fluids or gases within a system of pipes or machinery.

“He turned the valve to shut off the water before fixing the leak.”

“The engineer adjusted the pressure relief valve to ensure the steam did not exceed the safety limits of the boiler system.”

Usage

Often used with verbs like 'open', 'close', or 'turn'.

02anatomy

B2 · Medicine

n. a part of the heart or a vein that keeps blood flowing in the right direction.

n. a membranous fold or flap in a hollow organ or vessel that maintains the unidirectional flow of bodily fluids.

“The doctor checked the patient's heart valves to make sure they were working correctly.”

“Mitral valve prolapse occurs when the flaps of the heart's mitral valve do not close smoothly or evenly.”

Usage

Commonly appears in medical contexts regarding the heart or circulatory system.

Synonyms

03vacuum tube

C1 · Computing

n. an old-fashioned electronic part used in early radios and computers.

n. an electron tube consisting of a sealed glass or metal enclosure used to control electron flow.

“The old radio still uses glass valves instead of modern chips.”

“Early mainframe computers relied on thousands of thermionic valves, which generated immense heat and required frequent replacement.”

British English · Technical

Teaching tip

This is the standard British term for what Americans call a 'vacuum tube'.

Synonyms

vacuum tubetube

04biology

C2 · Science

n. one of the two parts of a shell, like those on a clam or an oyster.

n. one of the distinct, usually hinged, shells of a bivalve mollusc or the shell-like parts of certain other organisms.

“The clam uses strong muscles to keep its two valves tightly shut.”

“The fossil record provides clear evidence of how the hinge mechanism between the two valves evolved over millions of years.”

Technical

Synonyms

05to regulate flow

C2 · Technical

v. to control the flow of something using a valve.

v. to regulate or control the passage of a fluid or gas through the use of valves.

“The system is designed to valve the gas automatically if the pressure drops.”

“The technician had to manually valve the intake to prevent the chemical solution from overflowing the primary tank.”

Formal

Synonyms

Real-World Examples

“It was only after he returned to his home in Copenhagen that a doctor examined him and discovered that a valve in his heart was broken, and filling his lungs with blood.”
The Guardian · 17 Sept 2026
“And when a clot forms on your heart valves, “that leads to a condition called infective endocarditis.”
The Guardian · 11 May 2026

Etymology

From Middle English valve, from Latin valva (“double door, valve”). Doublet of valva.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Domains

AnatomyBiologyBotany

This entry

Level
B2 · Upper Intermediate
Frequency
Common
Updated

Scan code

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English Reference