1. Same as ocean. 2. A subdivision of an ocean. All seas except “inland seas” are physically interconnected parts of the earth's total saltwater system. Two types are distinguished, mediterranean and adjacent. Mediterraneans are groups of seas, collectively separated from the major water body as an individual sea. Adjacent seas are those connected individually to the larger body. 3. Same as state of the sea. 4. Sea surface waves within their fetch; opposed to swell. See fully developed sea.