Bay

Bay is properly applied to an indentation of the sea into the land, with an opening wider than the depth. A gulf is understood to be deeper than a bay, and has often a narrow opening. These terms are often loosely applied; Baffin Bay, e.g., is really a gulf. When the body of water is large, and the entrance narrow, it becomes a shut sea, as the Baltic, the Red Sea, &c. Hudson Bay, the Persian Gulf, and the Gulf of Mexico, might with propriety be termed seas.