1. (尤指青少年的)违法行为，犯罪行为
Delinquency is criminal behaviour, especially that of young people.

2. 逾期未还债务（或未缴税款）
Delinquency is failure to pay a debt or tax.

1. an antisocial misdeed in violation of the law by a minor

Synonym: juvenile delinquency

2. a tendency to be negligent and uncaring

e.g. he inherited his delinquency from his father
his derelictions were not really intended as crimes
his adolescent protest consisted of willful neglect of all his responsibilities

Synonym: derelictionwillful neglect

3. nonpayment of a debt when due