An example of a socket is the hole in the wall into which a plug goes.
A light-bulb socket.
The socket for a lightbulb, of the eye, of the hipbone, etc.
Origin of socket
- Middle English soket from Anglo-Norman spearhead diminutive of soc plowshare probably of Celtic origin sū- in Indo-European roots
From American Heritage Dictionary of the English Language, 5th Edition