Ermine (5)
I believe the answer is:
stoat
'ermine' is the definition.
(I know that stoat is a type of ermine)
This is all the clue.
(Other definitions for stoat that I've seen before include "European ermine" , "Ermine in summertime?" , "furry animal" , "Member of the weasel family" , "Eating rabbit, he" .)