Real stinker (5)
I believe the answer is:
skunk
'real stinker' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for skunk that I've seen before include "Animal with foul scent" , "Smelly animal" , "Evil-smelling animal of N America" , "Marijuana - scumbag" , "American animal notorious for its bad smell" .)