amphetamine
noun [countable, uncountable]a drug that makes you feel excited and full of energy, used to treat certain medical conditions or taken illegally as a stimulant 苯丙胺（中枢兴奋药）；安非他明 Word Origin1930s: abbreviation of its chemical name, a(lpha-)m(ethyl) phe(ne)t(hyl)amine.