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Phonetics
/ˈstɒpkɒk/
/ˈstɑpkɑk/
noun
A valve, tap or faucet which regulates the flow of liquid or gas through a pipe.
A main shutoff for water to a home from a municipal supply. Usually these valves exist in pairs, one outside the property boundary and one inside the property boundary.
Example: If you have a burst pipe turn the water off at the stopcock.