Source : Webster's Revised Unabridged Dictionary (1913)

Stopcock \Stop"cock`\, n.
   1. 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.

   2. The turning plug, stopper, or spigot of a faucet. [R.]

Source : WordNet®

stopcock
     n : faucet consisting of a rotating device for regulating flow
         of a liquid [syn: {cock}, {turncock}]