Staff whip smelly animal (7)
I believe the answer is:
polecat
'smelly animal' is the definition.
(I've seen this before)
'staff whip' is the wordplay.
'staff' becomes 'pole' (both can mean a stick).
'whip' becomes 'cat' (cat o' nine tails, cat for short is a type of whip).
'pole'+'cat'='POLECAT'
(Other definitions for polecat that I've seen before include "Weasel-like mammal" , "Unpleasant-smelling woodland animal" , "Weasel-like creature" , "Malodorous carnivore" , "weaselly creature" .)