To do with the sense of smell (9)
I believe the answer is:
olfactory
'to do with the sense of smell' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for olfactory that I've seen before include "Pertaining to the sense of smell" , "concerned with smell" , "Detecting scent" , "Fool Tracy (anag) - relating to the sense of smell" , "Smelling" .)