ephedrinePronunciation: /ˈɛfədriːn/Definition of ephedrine noun [mass noun] Medicine a crystalline alkaloid drug obtained from some ephedras. It causes constriction of the blood vessels and widening of the bronchial passages, and is used to relieve asthma and hay fever. Chemical formula: C10H15NO Origin: late 19th century: from ephedra + -ine4ephedrine in other Oxford dictionaries Definition of ephedrine in the US English dictionary
