plural valves
1
: a mechanical device that controls the flow of liquid, gas, etc., by opening and closing
They turned off the main water valve to the house.
2
: a device in some musical instruments (such as trumpets) that you press to play different notes
3
medical
: a structure in the heart, stomach, etc., that temporarily stops the flow of fluid or that allows fluid to move in one direction only
a heart valve
4
British
: vacuum tube
Cite this Entry
“Valve.” Merriam-Webster.com Simple Definition, Merriam-Webster, https://www.merriam-webster.com/simple/valve. Accessed 21 Jun. 2026.
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