Complete rascal not breaking law! (8)
I believe the answer is:
implicit
'complete' is the definition.
(thesaurus)
'rascal not breaking law' is the wordplay.
'rascal' becomes 'imp' (synonyms).
'not breaking law' becomes 'licit' (I can't justify this - if you can you should believe this answer much more).
'imp'+'licit'='IMPLICIT'
Can you help me to learn more?
(Other definitions for implicit that I've seen before include "Understood but not openly stated" , "I clip Tim (anag.)" , "meaning is obvious?" , "Not actually stated" , "Implicit" .)