bryonin

from The Century Dictionary.

• noun A white intensely bitter principle, a glucoside (C₄₈H₈₀O₁₉) extracted from the root of Bryonia alba and B. dioica. Also spelled brionin, brionine.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Chem.) A bitter principle obtained from the root of the bryony (Bryonia alba and Bryonia dioica). It is a white, or slightly colored, substance, and is emetic and cathartic.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun organic chemistry An emetic substance obtained from bryony root.