He ran a novel criminal class (5)
I believe the answer is:
fagin
'he ran a novel criminal class' is the definition.
The definition suggests a singular noun which matches the answer.
This is all the clue.
Can you help me to learn more?
(Other definitions for fagin that I've seen before include "he hanged" , "Gang leader (Oliver Twist)" , "Gang-leader" , "Character in Oliver Twist" , "Criminal in Oliver Twist" .)