A Juvenile delinquent (n.) is a juvenile who should have been punished more, or a delinquent who should have been punished less.
A Juvenile delinquent (n.) is a minor who creates a major problem.
A Juvenile delinquent (n.) is very good at being no good.
A Juvenile delinquent (n.) is a youngster whose childhood has made him a child hoodlum.
A Juvenile delinquent (n.) gives up stealing bases when be starts stealing cars.
A Juvenile delinquent (n.) is merely misguided if you're the parent, but really murderous if you're the victim.
A Juvenile delinquent (n.) sometimes tries to do right, but only because he thinks it is wrong.