from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Any of various marsh plants of the genus Polygonum, having sheathlike stipules and small, densely clustered pink, white, or green flowers.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Any of more than a dozen species of the genus Polygonum.
from the GNU version of the Collaborative International Dictionary of English
- n. An acrid plant of the genus Polygonum (P. Hydropiper), which produces smarting if applied where the skin is tender.
from The Century Dictionary and Cyclopedia
- n. The water-pepper, Polygonum Hydropiper, a weed of wet places in the Old World and the New.
smart + weed (Wiktionary)