adapter

Concise Oxford English Dictionary © 2008 Oxford University Press:
adaptor /əˈdaptə(r)/ (also adapter)

▶noun

• 1 a device for connecting pieces of equipment.

  ■ Brit. a device for connecting more than one plug at a time or plugs of a non-standard type to an electrical socket.

• 2 a person who adapts a text for filming, broadcasting, or the stage.