Sea

A sea is either a large expanse of saline water connected with an ocean, or a large, usually saline, lake that lacks a natural outlet such as the Caspian Sea and the Dead Sea. The term is used colloquially as synonymous with ocean, as in "the tropical sea" or "down to the sea shore", or even "sea water" to refer to water of the ocean. Large lakes, such as the Great Lakes, are sometimes referred to as inland seas. Many seas are marginal seas, in which currents are caused by ocean winds; others are mediterranean seas, in which currents are caused by differences in salinity and temperature.