Rascal lived badly (5)
I believe the answer is:
devil
'rascal' is the definition.
(thesaurus)
'lived badly' is the wordplay.
'badly' is an anagram indicator.
'lived' anagrammed gives 'DEVIL'.
(Other definitions for devil that I've seen before include "Archfiend" , "Lived with Satan" , "Old Nick, Satan" , "Wicked spirit" , "Beast" .)