BURDOCK
burdock, clotbur
(noun) any of several erect biennial herbs of temperate Eurasia having stout taproots and producing burs
Source: WordNet® 3.1
Etymology
Noun
burdock (plural burdocks)
Any of the species of biennial thistles in the genus Arctium.
Source: Wiktionary
Bur"dock, n. Etym: [Bur + dock the plant.] (Bot.)
Definition: A genus of coarse biennial herbs (Lappa), bearing small burs
which adhere tenaciously to clothes, or to the fur or wool of
animals.
Note: The common burdock is the Lappa officinalis.
Source: Webster’s Unabridged Dictionary 1913 Edition