1. stopcock - Noun
2. stopcock - Verb
A bib, faucet, or short pipe, fitted with a turning stopper or plug for permitting or restraining the flow of a liquid or gas; a cock or valve for checking or regulating the flow of water, gas, etc., through or from a pipe, etc.
The turning plug, stopper, or spigot of a faucet.
Source: Webster's dictionary