Murder party at home (2,2)
I believe the answer is:
do in
'murder' is the definition.
('do in' can mean to kill)
'party at home' is the wordplay.
'party' becomes 'do' (do can informally mean a party).
'at home' becomes 'in' ('I'm in' can mean 'I'm at home').
'do'+'in'='DO IN'
(Other definitions for do in that I've seen before include "Get rid of" , "Knock off" , "Murder" .)