Satan lived badly (5)
I believe the answer is:
devil
'satan' is the definition.
(I know that satan can be written as devil)
'lived badly' is the wordplay.
'badly' indicates anagramming the letters (letters in the wrong order).
'lived' anagrammed gives 'DEVIL'.
(Other definitions for devil that I've seen before include "Demon" , "Terror" , "Archfiend" , "Imp" , "Lucifer" .)