white hellebore
noun
The white-flowered Eurasian herbaceous plant Veratrum album (family Melanthiaceae), the toxic root of which has been used medicinally (especially as a purgative) and as a pesticide; (in later use also) any of various other plants of the genus Veratrum, especially (more fully American white hellebore) V. viride of North America; frequently attributive.
Origin
Late Middle English; earliest use found in Guy de Chauliac's Grande Chirurgie. After classical Latin elleborus albus (Pliny).