(Bot.) The name of several poisonous umbelliferous herbs having finely cut leaves and small white flowers, as the Cicuta maculata, Cicuta bulbifera, and Cicuta virosa, and the Conium maculatum. See Conium. Note: The potion of hemlock administered to Socrates is by some thought to have been a decoction of Cicuta virosa, or water hemlock, by others, of Conium maculatum.