Courted sweetheart leaving for club? (4)
I believe the answer is:
wood
'for club?' is the definition.
(wood is a kind of club)
'courted sweetheart leaving' is the wordplay.
'courted' becomes 'wooed' ('woo' can be a synonym of 'court').
'sweetheart' becomes 'e' (the heart/centre of 'sweet').
'leaving' is a deletion indicator.
'wooed' with 'e' taken away is 'WOOD'.
(Other definitions for wood that I've seen before include "Timber" , "Cooing bird" , "Material from trees" , "Driver, perhaps" , "deal?" .)