Stupid and empty party after party (4)
I believe the answer is:
dopy
'stupid' is the definition.
('dopy' can be similar in meaning to 'stupid')
'empty party after party' is the wordplay.
'empty' says to hollow out the word (remove centre letters).
'after' means one lot of letters go next to another.
'party' becomes 'do' (do is a kind of party).
'party' with its middle removed is 'py'.
'py' put after 'do' is 'DOPY'.
'and' acts as a link.
(Other definitions for dopy that I've seen before include "potty" , "Stupid" , "Stupefied" , "Muddled" .)