Twice finished burnt? (8)
I believe the answer is:
overdone
'burnt?' is the definition.
The definition and answer can be both to do with social activities as well as being past participle verbs.
Perhaps you can see an association between them that I don't see?
'twice finished' is the wordplay.
'twice' becomes 'over' (I can't explain this - if you can you should believe this answer much more).
'finished' becomes 'done' (both can mean completed).
'over'+'done'='OVERDONE'
(Other definitions for overdone that I've seen before include "Hammed up" , "Cooked too long" , "Cooked too much or carried too far" , "really a bit much!" , "Cooked to excess" .)