1 a a prickly clinging seed-case or flower-head. b any plant producing these.
2 a person hard to shake off.
3 = BURR n. 2.
Phrases and idioms:
bur oak a N. American oak, Quercus macrocarpa with large fringed acorn-cups.
Etymology: ME: cf. Da. burre bur, burdock, Sw. kard-borre burdock
Useful english dictionary. 2012.