What is the meaning of hemlock?

noun

• Poisonous drug derived from an Eurasian plant of the genus Conium.
  • usage: "Socrates refused to flee and died by drinking hemlock"
• Large branching biennial herb native to Eurasia and Africa and adventive in North America having large fernlike leaves and white flowers; usually found in damp habitats; all parts extremely poisonous.
  • synonyms: poison hemlock, poison parsley, California fern, Nebraska fern, winter fern, Conium maculatum
• Soft coarse splintery wood of a hemlock tree especially the western hemlock.
• An evergreen tree.
  • synonyms: hemlock tree