Bouquet to be dispatched, expressed (5)
I believe the answer is:
scent
'bouquet' is the definition.
(thesaurus)
'dispatched expressed' is the wordplay.
'dispatched' becomes 'sent' (I've seen this before).
'expressed' indicates a 'sounds like' (homophone) clue.
'sent' sounds like 'SCENT'.
'to be' is the link.
(Other definitions for scent that I've seen before include "Distinctive odour" , "Get wind of" , "Clue" , "Fragrance" , "Animal smell" .)