Clarified pig fat (4)
I believe the answer is:
lard
'clarified pig fat' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for lard that I've seen before include "F [FAT]" , "Clarified pig fat" , "Soft white semisolid fat" , "White cooking fat" , "Pig-fat" .)