Successful party succeeds without women (3)
I believe the answer is:
ins
'successful party' is the definition.
(I've seen this in another clue)
'succeeds without women' is the wordplay.
'succeeds' becomes 'wins' (I've seen this in another clue).
'without' is a deletion indicator.
'women' becomes 'w' (standard abbreviation).
'wins' with 'w' taken away is 'INS'.
(Other definitions for ins that I've seen before include "- - and outs" , "Party of government" , "Ruling party" .)