delinquent

a young offender

guilty of a minor misdeed

• “delinquent minors”

failing in what duty requires

• “derelict (or delinquent) in his duty”
• “neglectful of his duties”
• “remiss of you not to pay your bills”

persistently bad

• “school for delinquent boys”

past due; not paid at the scheduled time

• “an overdue installment”
• “a delinquent account”