Drink alone in a provocative way (9)
I believe the answer is:
teasingly
'in a provocative way' is the definition.
'drink alone' is the wordplay.
'drink' becomes 'tea' (tea is a kind of drink).
'alone' becomes 'singly'.
'tea'+'singly'='TEASINGLY'
(Other definitions for teasingly that I've seen before include "not to be taken seriously!" , "how some jokers behave" , "in playful fashion" .)