n. - A poisonous glucoside found in many plants, as in the root
of soapwort (Saponaria), in the bark of soap bark (Quillaia), etc. It
is extracted as a white amorphous powder, which occasions a soapy
lather in solution, and produces a local anaesthesia. Formerly called
also struthiin, quillaiin, senegin, polygalic acid, etc. By extension,
any one of a group of related bodies of which saponin proper is the
type.