cock·le·bur noun orcock·le·burr\ˈkäkəl, ˈkəkəl+ˌ-\ (-s) Etymology:cockle (I) + bur 1.: a plant of the genus Xanthium 2.: the prickly fruit of a cocklebur that readily attaches itself to any passing object by means of the stiff hooked spines with which it is clothed