Non-PC (3)
I believe the answer is:
mac
'non-pc' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for mac that I've seen before include "Waterproof coat (colloq.)" , "A Gaelic son, often in name" , "one used in shower?" , "Coat - computer" , "Waterproof raincoat, in short" .)