Advance with a bouquet (6)
I believe the answer is:
ascent
'advance' is the definition.
(thesaurus)
'with a bouquet' is the wordplay.
'with' says to put letters next to each other.
'bouquet' becomes 'scent' (I've seen this before).
'a'+'scent' is 'ASCENT'.
(Other definitions for ascent that I've seen before include "Acclivity" , "Maybe promotion" , "Stance (anag)" , "A climb or way up" , "lift" .)