noun
delinquency; misconduct; delinquent behavior
Refers to juvenile delinquency or general misbehavior, often in legal or educational contexts.
彼は不良行為で補導された。
He was taken into custody for delinquent behavior.
学校では不良行為は厳しく罰せられる。
Misconduct is strictly punished at school.
Compound of 不良 (bad, delinquent) and 行為 (act, conduct).