Good man needing a good party (4)
I believe the answer is:
Here is my best explanation:
'party' is the definition.
(stag party is a kind of party)
'good man needing a good' is the subsidiary indication.
'good man' becomes 'st' (**).
'needing' says to put letters next to each other.
'a good' becomes 'ag' (I've seen this in other clues).
(Other definitions for stag that I've seen before include "Antlered animal", "Animal, male only", "This party is for men only", "Stockmarket operator gambling on a quick profit", "Unaccompanied man at party", "Adult male deer, often with antlers", "Stock market speculator", "Male deer; speculator", "For men only" and "Male animal".)