Nature's bandage (4)
I believe the answer is:
scab
'nature's bandage' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for scab that I've seen before include "part of healing process" , "cover" , "Derogatory term for a strike-breaker" , "Ignorer of strike" , "Strike breaker" .)