Definition of "black horehound" [black horehound]

• A Eurasian perennial herb (Ballota nigra) in the mint family, having hairy, strong-smelling foliage and clusters of pinkish-purple flowers. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.