hydraulic cement: a cement that hardens under water; made by heating limestone and clay in a kiln and pulverizing the result
cement: a building material that is a powder made of a mixture of calcined limestone and clay; used with water and sand or gravel to make concrete and mortar
geoduck: a large edible clam found burrowing deeply in sandy mud along the Pacific coast of North America; weighs up to six pounds; has siphons that can extend to several feet and cannot be withdrawn into the shell