The term 'cockle' can refer to two different things. The first is a BIVALVE, which is a type of mollusk with two shells that are hinged together. Bivalves are found in both salt and fresh water and are commonly eaten as seafood. The second definition of cockle is an OAST, which is a kiln used for drying hops in the brewing process. Oasts were traditionally built in the shape of a cone and had a vent at the top to allow smoke to escape.