Hore″hound′ (?), n. [OE. horehune, AS. hārhune; hār hoar, gray + hune horehound; cf. L. cunila a species of organum, Gr. �, Skr. kn�y to smell.] (Bot.) A plant of the genus Marrubium (M. vulgare), which has a bitter taste, and is a weak tonic, used as a household remedy for colds, coughing, etc. [Written also hoarhound.]
Fetid horehound, orBlack horehound, a disagreeable plant resembling horehound (Ballota nigra). — Water horehound, a species of the genus Lycopus, resembling mint, but not aromatic.