Hare hair (3)
I believe the answer is:
fur
'hare hair' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for fur that I've seen before include "Eg, chinchilla" , "Animal pelt" , "Mink or ermine, say" , "Hair covering animal's body" , "Deposit inside kettles" .)