A powerful and very poisonous vegetable alkaloid found in
   the hemlock (Conium maculatum) and extracted as a colorless oil,
   C8H17N, of strong repulsive odor and acrid taste. It is regarded as a
   derivative of piperidine and likewise of one of the collidines. It
   occasions a gradual paralysis of the motor nerves. Called also coniine,
   coneine, conia, etc. See Conium, 2.