Launch a perfume (6)
I believe the answer is:
ascent
'launch' is the definition.
(eg a rocket ascending)
'a perfume' is the wordplay.
'perfume' becomes 'scent' (synonyms).
'a'+'scent'='ASCENT'
(Other definitions for ascent that I've seen before include "Acclivity" , "Upwards motion" , "Upward slope" , "rising?" , "(A) climb (up mountain)" .)