noun
illegal drug
Refers to substances prohibited by law, such as narcotics or controlled substances. Often used in legal or news contexts.
違法薬物の所持で逮捕された。
He was arrested for possession of illegal drugs.
違法薬物の使用は健康を害する。
Using illegal drugs harms your health.
Compound of 違法 (illegal) and 薬物 (drug). The term is a straightforward modern coinage.