amphetamine /æmˈfɛt.ə.miːn/ noun4 •The racemic freebase of 1-phenylpropan-2-amine; an equal parts mixture of levoamphetamine and dextroamphetamine in their pure amine forms. •A potent central nervous system stimulant of the phenethylamine chemical class that is used to treat ADHD, narcolepsy, and obesity. •(informal) Any mixture of the two amphetamine enantiomers, dextroamphetamine and levoamphetamine. •(informal, nonstandard) Referring to a substituted amphetamine; a member of the amphetamine class of chemicals. formsamphetamines