The Collaborative International Dictionary of English v.0.48:
Betony \Bet"o*ny\, n.; pl. Betonies. [OE. betony, betany, F. betoine, fr. L. betonica, vettonica.] (Bot.) A plant of the genus Betonica (Linn.). [1913 Webster] Note: The purple or wood betony (Betonica officinalis, Linn.) is common in Europe, being formerly used in medicine, and (according to Loudon) in dyeing wool a yellow color. [1913 Webster]