Source : Webster's Revised Unabridged Dictionary (1913)

Burdock \Bur"dock\, n. [Bur + dock the plant.] (Bot.)
   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 : WordNet®

burdock
     n : any of several erect biennial herbs of temperate Eurasia
         having stout taproots and producing burs [syn: {clotbur}]