Perfume dispatched, so we hear (5)
I believe the answer is:
scent
'perfume' is the definition.
(I know that perfume can be written as scent)
'dispatched so we hear' is the wordplay.
'dispatched' becomes 'sent' (I've seen this in another clue).
'so we hear' shows a homophone (sound like).
'sent' is a homophone of 'SCENT'.
(Other definitions for scent that I've seen before include "Perfume for the tracker" , "Fragrance" , "Clue" , "Animal smell" , "Track; aroma" .)