Two imbeciles at home revealing killer (8)
I believe the answer is:
assassin
'killer' is the definition.
(assassin is a kind of killer)
'two imbeciles at home' is the wordplay.
'two' says to double the letters.
'imbeciles' becomes 'ass' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'at home' becomes 'in' (similar in meaning).
'ass' doubled is 'assass'.
'assass'+'in'='ASSASSIN'
'revealing' is the link.
(Other definitions for assassin that I've seen before include "Bravo!" , "Political murderer" , "Terrorist" , "Killer of prominent figure" , "Booth, for example" .)