Money shut up after party (4)
I believe the answer is:
dosh
'money' is the definition.
(I've seen this before)
'shut up after party' is the wordplay.
'shut up' becomes 'sh'.
'after' is a charade indicator (letters next to each other).
'party' becomes 'do' (do is a kind of party).
'sh' after 'do' is 'DOSH'.
(Other definitions for dosh that I've seen before include "Bread - gravy - dough" , "Moolah (slang)" , "Contents of purse" , "Brass" , "Lolly (slang)" .)