Stoat-like mammal (6)
I believe the answer is:
weasel
'stoat-like mammal' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for weasel that I've seen before include "Carnivore -- saw eel (anag)" , "Animal; sly person" , "Stoat-like mammal - treacherous type" , "Predator" , "One deceiving" .)