noun which may take the genitive case particle 'no', na-adjective, noun
bad; poor; inferior; defective
Used for quality, condition, performance, or outcomes that are below standard. Often appears in compounds like 不良品 (defective product) or 成績不良 (poor academic performance).
この製品は不良品だったので交換してもらった。
This product was defective, so I had it replaced.
He was hospitalized due to poor health.
noun, noun which may take the genitive case particle 'no', na-adjective
Refers to a person, especially a young person, who engages in antisocial or criminal behavior. Commonly used in 不良少年 (juvenile delinquent) or 不良グループ (gang of delinquents).
彼は昔、不良だったが今は真面目に働いている。
He used to be a delinquent, but now he works seriously.
夜の公園には不良がたむろしている。
Delinquents hang around the park at night.