aconitum

noun

1. any of a genus (Aconitum) of poisonous plants of the buttercup family, with blue, purple, or yellow hoodlike flowers; monkshood; wolfsbane
2. a rapidly acting poisonous drug usually made from the dried roots of a European monkshood (Aconitum napellus) and formerly used as a cardiac and respiratory sedative
   also aconitum