Two parties, one completely dead? (4)
I believe the answer is:
dodo
'one completely dead?' is the definition.
(the dodo is an extinct bird)
'two parties' is the wordplay.
'two parties' means two substitutions for 'party'.
'party' becomes 'do' (do is a kind of party).
'party' becomes 'do' (do is a kind of party**).
'do'+'do'='DODO'
(Other definitions for dodo that I've seen before include "Ultra-conservative" , "Bird (whose style of very out of fashion)" , "Flightless bird, extinct since the 17th century" , "one very dead!" , "Idiot" .)