methamphetamine
noun [ U ] uk/ˌmeθ.æmˈfet.ə.miːn/ us/ˌmeθ.æmˈfet̬.ə.miːn/ (also slang crystal meth, meth)
甲基苯丙胺（刺激精神和身体的药物，容易让人上瘾）
a drug that makes your mind and body more active. It is addictive (= you cannot stop taking it when you have started) and some people take it illegally.