SAPONIN

[sa.po.nin] n [F saponine, fr. L sapon-, sapo] (1831): any of various mostly toxic glucosides that occur in plants (as soapwort or soapbark) and are characterized by the property of producing a soapy lather; esp: a hygroscopic amorphous saponin mixture used esp. as a foaming and emulsifying agent and detergent