(bûr)
1. Bot. A rough or prickly flower head, or the like, as of the chestnut and burdock.
2. The burdock or other plant that bears burs.
3. A protuberance; lump; specifically, a knot or excrescence on a tree.
4. An impediment or unwelcome adherent.
—v.t. burred, bur·ring To remove burs from, as wool. Also spelled burr. ◆ Homophones: birr, burr. [<Scand. Cf. Dan. borre bur.]

(bûr)
See BURR¹.