Oscar event oration, having a bouquet (7)
I believe the answer is:
odorant
'having a bouquet' is the definition.
(a bouquet is the smell or odour of wine)
'oscar event oration' is the wordplay.
'oscar' becomes 'O' (phonetic alphabet: alpha, bravo, charlie etc.).
'event' becomes 'do' (do is a kind of event).
'oration' becomes 'rant' (rant is a kind of oration).
'o'+'do'+'rant'='ODORANT'
(Other definitions for odorant that I've seen before include "Aromatic" , "Tornado (anag)" , "may create a stink?" , "Something emitting a strong smell" .)