stopcock

/ˈstɑpˌkɑk/
noun
  1. A valve used to control the flow of a liquid or gas through a pipe, often by turning a handle.
    • She checked the stopcock in the basement to make sure the outdoor faucet wouldn't freeze.
    • The plumber turned the stopcock to shut off the water supply before fixing the leak.
    • In an emergency, you can use the stopcock to stop the gas flow to the stove.
Synonyms
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