Bother at a party (3)
I believe the answer is:
ado
'bother' is the definition.
(both can mean fuss or commotion)
'at a party' is the wordplay.
'at' is a charade indicator (letters next to each other).
'party' becomes 'do' (do can informally mean a party).
'a' put next to 'do' is 'ADO'.
(Other definitions for ado that I've seen before include "Goings-on" , "Pother" , "Nothing caused much around 1598" , "Fuss or bustle" , "Fuss, bother" .)