: any of various chiefly marine bivalve mollusks (family Cardiidae) having a shell with convex radially ribbed valves; especially: a common edible European bivalve (Cerastoderma edule syn. Cardium edule)
Middle English kokell, ultimately from Middle French coquillé wavy or rounded like a shell, from coquille
First Known Use: 15th century
Great heart cockle (Dinocardium robustum)—Harry Rogers
Any of approximately 250 species (family Cardiidae) of marine bivalves distributed worldwide. They range in diameter from about 0.5 in. (1 cm) to about 6 in. (15 cm). The two valves of the shell are equal in size and shape and range in colour from brown to red or yellow. Most species live just below the low-tide line, though some have been obtained from depths of more than 1,500 ft (500 m) or in the intertidal zone. Many species are marketed commercially for their meat.