Pig's pad (3)
I believe the answer is:
sty
'pig's pad' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for sty that I've seen before include "Pig-pen and infection on the eyelid" , "Swinish place" , "Eye ailment or pig's home" , "Pig home or eye sore" , "Pig's enclosure" .)