Demand silence on party money (4)
I believe the answer is:
dosh
'money' is the definition.
(I know that money can be written as dosh)
'demand silence on party' is the wordplay.
'demand silence' becomes 'sh' (to sh someone is to demand silence from them).
'on' is a charade indicator (letters next to each other).
'party' becomes 'do' (do is a kind of party).
'sh' put after 'do' is 'DOSH'.
(Other definitions for dosh that I've seen before include "Moolah (slang)" , "Shod (anag.)" , "cash" , "Lolly (slang)" , "Ready" .)