papaverine n 1: an alkaloid medicine (trade name Kavrin) obtained from opium; used to relax smooth muscles; it is nonaddictive [syn: {papaverine}, {Kavrin}]
Papaverine \Pa*pav"er*ine\, n. (Chem.) An alkaloid found in opium. It has a weaker therapeutic action than morphine. [1913 Webster]