noun
Refers to chemically synthesized narcotics or psychoactive substances, often illicit. Designer drugs is also used.
See also: デザイナードラッグ
警察は新しい合成麻薬の流通を警戒している。
The police are on alert for the distribution of new synthetic drugs.
デザイナードラッグ specifically refers to designer drugs created to circumvent existing drug laws, while 合成麻薬 is a broader term for any synthetic narcotic.
Compound of 合成 (synthesis) and 麻薬 (narcotic).