1.NounA toxic compound of the alkaloid class obtained chiefly from the bark and stems of a South American vine (Chondrodendron tomentosum of the family Menispermaceae) that in its dextrorotatory form constitutes the chief active constituent of curare and used in the form of its hydrated hydrochloride C37H41ClN2O6·HCl·5H2O to produce relaxation of voluntary muscles before surgery and in tetanus, encephalitis, and poliomyelitis.