Fuss made by the inner man at a party (3)
I believe the answer is:
ado
'fuss' is the definition.
(synonyms)
'at a party' is the wordplay.
'at' means one lot of letters go next to another.
'party' becomes 'do' (do is a kind of party).
'a'+'do' is 'ADO'.
'made by the inner man' acts as a link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for ado that I've seen before include "Rapid bustling commotion" , "stew is provided" , "agitation" , "'Much ... About Nothing, Shakespeare play (3)'" , "Pother" .)