Delinquent

Part of speech: noun (n.)

One who fails or neglects to perform his duty; an offender or transgressor; one who commits a fault or a crime; a culprit. A delinquent ought to be cited in the place or jurisdiction where the delinquency was committed. Ayliffe.

Part of speech: adjective (a.)

Failing in duty; offending by neglect of duty.