Fat chap embracing a redhead (4)
I believe the answer is:
lard
'fat' is the definition.
(lard is a kind of fat)
'chap embracing a redhead' is the wordplay.
'chap' becomes 'lad' (**).
'embracing' is an insertion indicator.
'a redhead' becomes 'r' (the head/first letter of 'red').
'lad' going around 'r' is 'LARD'.
(Other definitions for lard that I've seen before include "Pig-fat" , "Animal fat" , "Clarified pig fat" , "F [FAT]" , "Pig's fat" .)