Definition of: hellebore

(hel′ə·bôr, -bōr) noun
1. A perennial herb (genus Helleborus) of the crowfoot family having serrated leaves and large flowers. Cultivated species are, in the United States, the green hellebore (H. viridis), and in Europe, the black hellebore or Christmas rose (H. niger), the black roots of which are a powerful cathartic.
2. Any of certain herbs (genus Veratrum) of the lily family whose dried rootstocks yield poisonous alkaloids of use in medicine and as insecticides; especially the American or green hellebore (V. viride) and the European white hellebore (V. album): also called false hellebore.
3. The powdered root of the American hellebore, used to destroy plant vermin. [<L helleborus <Gk. helleboros]