Good man needing a good party (4)
I believe the answer is:
stag
'party' is the definition.
(I've seen this before)
'good man needing a good' is the wordplay.
'good man' becomes 'st'.
'needing' means one lot of letters go next to another.
'a good' becomes 'ag' (I've seen this in other clues).
'st'+'ag'='STAG'
(Other definitions for stag that I've seen before include "Share speculator" , "Male at party?" , "Antlered animal" , "Sort of party" , "Animal - for men only" .)