Plug receiver (6)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
socket
'plug receiver' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for socket that I've seen before include "Counterpart to a plug" , "Light bulb holder" , "Power point" , "Hollow for a ball or plug" , "Receptacle where something is inserted" .)