delinquent -- (guilty of a misdeed; "delinquent minors")
derelict, delinquent, neglectful, remiss -- (failing in what duty requires; "derelict (or delinquent) in his duty"; "neglectful of his duties"; "remiss of you not to pay your bills")
delinquent, overdue -- (past due; not paid at the scheduled time; "an overdue installment"; "a delinquent account")