Perfume gets posted, we hear (5)
I believe the answer is:
scent
'perfume' is the definition.
('scent' can be a synonym of 'perfume')
'posted we hear' is the wordplay.
'posted' becomes 'sent' ('send' can be a synonym of 'post').
'we hear' shows a homophone (sound like).
'sent' is a homophone of 'SCENT'.
'gets' is the link.
(Other definitions for scent that I've seen before include "Whiff" , "Distinctive aroma" , "Number of clues" , "Perfume for the tracker" , "Distinctive odour" .)