Wind up, seeing deficit reversed in seedy club! (8)
I believe the answer is:
dissolve
'wind up' is the definition.
(I've seen this before)
'deficit reversed in seedy club' is the wordplay.
'deficit' becomes 'loss' (I've seen this before).
'reversed' says the letters should be written in reverse.
'in' is an insertion indicator.
'seedy club' becomes 'dive'.
'loss' written backwards gives 'ssol'.
'ssol' inserted into 'dive' is 'DISSOLVE'.
'seeing' acts as a link.
(Other definitions for dissolve that I've seen before include "Incorporate a solid into a liquid" , "Finish" , "Loves Sid (anag)" , "Disperse or melt in liquid" , "Break up a partnership, say" .)