Criminal to us, Abel is perfect (8)
I believe the answer is:
absolute
'is perfect' is the definition.
(synonyms)
'criminal to us abel' is the wordplay.
'criminal' indicates anagramming the letters.
'to'+'us'+'abel'='tousabel'
'tousabel' anagrammed gives 'ABSOLUTE'.
(Other definitions for absolute that I've seen before include "Sheer, utter or not limited" , "Perfect, complete, pure" , "rank" , "Total; unqualified" , "decided" .)