·noun A very poisonous alkaloid resembling brucine, obtained from various species of plants, especially from species of Loganiaceae, as from the seeds of the St. Ignatius bean (Strychnos Ignatia) and from nux vomica. It is obtained as a white crystalline substance, having a very bitter acrid taste, and is employed in medicine (chiefly in the form of the sulphate) as a powerful neurotic stimulant. Called also strychnia, and formerly strychnina.