Bunny's tail (4)
I believe the answer is:
scut
'bunny's tail' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for scut that I've seen before include "Deer's tail" , "Small tail as of rabbit" , "(Hare's) short upright tail" , "Short tail, such as rabbit's" , "Short tail of rabbit, deer etc" .)