1
a
: any of numerous mechanical devices by which the flow of liquid, gas, or loose material in bulk may be started, stopped, or regulated by a movable part that opens, shuts, or partially obstructs one or more ports or passageways
also
: the movable part of such a device
b
: a device in a brass instrument for quickly channeling air flow through an added length of tube in order to change the fundamental tone by some definite interval
c
chiefly British
: electron tube
2
[borrowed from Medieval Latin valva, going back to Latin]
: a bodily structure (such as the mitral valve) that closes temporarily a passage or orifice or permits movement of fluid in one direction only
3
[borrowed from New Latin valva, going back to Latin]
: one of the distinct usually hinged and movable pieces of which the shell of some shell-bearing animals (such as lamellibranch mollusks, brachiopods, and barnacles) consists
4
[borrowed from New Latin valva, going back to Latin]
a
: one of the segments or pieces into which a dehiscing capsule or legume separates
b
: the portion of various anthers (as of the barberry) resembling a lid
c
: one of the two encasing membranes of a diatom
5
archaic
: a leaf of a folding or double door
Examples of valve in a Sentence
They turned off the main water valve to the house.
Recent Examples on the Web
People who are at risk of endocarditis (inflammation of the lining of the heart valves and chambers).
—
Heather Jones, Verywell Health, 27 Sep. 2024
August's falling rates might have provided a relief valve for people who were waiting to move.
—Erin Alberty, Axios, 28 Oct. 2024
Congenital anomalies can include the following, according to the National Institute of Child Health and Human Development:
Heart defects, like missing or misshapen valves.
—Julia Gomez, USA TODAY, 23 Oct. 2024
Jefferson Chalmers was included in the city’s basement backup protection program, funded through the American Rescue Plan Act, to install backwater valves and sump pumps in homes hit hardest by heavy rainfall and flooding.
—Dana Afana, Detroit Free Press, 16 Oct. 2024
See all Example Sentences for valve 
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Heather Jones, Verywell Health, 27 Sep. 2024
August's falling rates might have provided a relief valve for people who were waiting to move.
—Erin Alberty, Axios, 28 Oct. 2024
Congenital anomalies can include the following, according to the National Institute of Child Health and Human Development:
Heart defects, like missing or misshapen valves.
—Julia Gomez, USA TODAY, 23 Oct. 2024
Jefferson Chalmers was included in the city’s basement backup protection program, funded through the American Rescue Plan Act, to install backwater valves and sump pumps in homes hit hardest by heavy rainfall and flooding.
—Dana Afana, Detroit Free Press, 16 Oct. 2024
See all Example Sentences for valve
Dictionary Entries Near valve
Cite this Entry
“Valve.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/valve. Accessed 22 Nov. 2024.
Copy CitationKids Definition
valve
noun1
: a bodily structure (as in a vein or the heart) that closes temporarily to prevent passage of material or that allows movement of a fluid in one direction only
2
a
: a mechanical device by which the flow of liquid, gas, or loose material in bulk may be controlled by a movable part
also
: the movable part of such a device
b
: a device in a brass musical instrument for quickly changing the tube length in order to make the tone higher or lower
3
: one of the separate pieces that make up the shell of some animals (as clams) and are often hinged
4
: one of the pieces into which a ripe seed capsule or pod separates
Medical Definition
valve
noun1
: a bodily structure (as the mitral valve) that closes temporarily a passage or orifice or permits movement of fluid in one direction only
2
: any of various mechanical devices by which the flow of liquid (as blood) may be started, stopped, or regulated by a movable part that opens, shuts, or partially obstructs one or more ports or passageways
also
: the movable part of such a device
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