wall plug

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun An electric socket, usually located in a wall, that is connected to and used as a source of electric power.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun UK A fixing that allows screws to be fitted into masonry walls, a dowel or screw anchor.
• noun US An electric socket.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun receptacle providing a place in a wiring system where current can be taken to run electrical devices