Dissenting criminal class is German, not French to begin with (13)
I believe the answer is:
nonconformist
'dissenting' is the definition.
(dissenting from conformity)
'criminal class is german not french to begin with' is the wordplay.
'criminal' becomes 'con' (abbreviation for 'convict').
'class' becomes 'form class' (synonyms).
'is german' becomes 'ist' ('is' in German).
'not french' becomes 'non' ('not' in French).
'to begin with' is a charade indicator (letters next to each other).
'con'+'form'+'ist'='conformist'
'conformist' after 'non' is 'NONCONFORMIST'.
(Other definitions for nonconformist that I've seen before include "One at odds with the Establishment" , "Breaking with established ideas" , "Christian?" , "Maverick" , "An original" .)