Bother with a party? (3)
I believe the answer is:
ado
'bother' is the definition.
(both can mean fuss or commotion)
'with a party?' is the wordplay.
'with' means one lot of letters go next to another.
'party?' becomes 'do' (do can informally mean a party).
'a'+'do' is 'ADO'.
(Other definitions for ado that I've seen before include "Flurry" , "puff ball!" , "Song and dance" , "'Much ... About Nothing, Shakespeare play (3)'" , "carry-on" .)