Noun | 1. | ephedrine - white odorless powdered or crystalline alkaloid from plants of the genus Ephedra (especially Ephedra sinica) or made synthetically; used as a bronchodilator to treat bronchitis and asthma bronchodilator - a drug that relaxes and dilates the bronchial passageways and improves the passages of air into the lungs alkaloid - natural bases containing nitrogen found in plants |