Optimistic of swilling gin, perhaps, at the dance (6)
I believe the answer is:
hoping
'optimistic of swilling' is the definition.
Although both the answer and definition are present participle verbs, I can't see how one could define the other.
'gin perhaps at the dance' is the wordplay.
'perhaps' indicates anagramming the letters.
'at' says to put letters next to each other (I've seen this in other clues).
'the dance' becomes 'hop' (hop is a kind of dance**).
'gin' anagrammed gives 'ing'.
'ing' after 'hop' is 'HOPING'.
Can you help me to learn more?
(Other definitions for hoping that I've seen before include "Expecting and wishing" , "Trusting, expecting" , "Desiring with an expectation of success" , "Having wish or desire for" .)