Cockle :: Cockle (n.) A bivalve mollusk, with radiating ribs, of the genus Cardium, especially C. edule, used in Europe for food; -- sometimes applied to similar shells of other genera..
Cocklebur :: Cocklebur (n.) A coarse, composite weed, having a rough or prickly fruit; one of several species of the genus Xanthium; -- called also clotbur..