Sheepskin (6)
I believe the answer is:
fleece
'sheepskin' is the definition.
(I know that sheepskin can be written as fleece)
This is all the clue.
(Other definitions for fleece that I've seen before include "Swindle; sheep's coat" , "Sheepskin - rook" , "Woolly coat of a sheep" , "A sheep's woolly coat" , "A sheep's wool coating" .)