What does "socket" mean?

Socket: Especially, the hollow tube or place in which a candle is fixed in the candlestick. And in the sockets oily bubbles dance. Dryden. Socket bolt (Mach.), a bolt that passes through a thimble that is placed between the parts connected by the bolt. -- Socket chisel. Same as Framing chisel. See under Framing. -- Socket pipe, a pipe with an expansion at one end to receive the end of a connecting pipe. -- Socket pole, a pole armed with iron fixed on by means of a socket, and used to propel boats, etc. [U.S.] -- Socket wrench, a wrench consisting of a socket at the end of a shank or rod, for turning a nut, bolthead, etc., in a narrow or deep recess.