Archipelago (n): 1) A large group of islands; a chain of islands. 2) A large body of water with many islands .
Ocean (n): The vast body of salt water that covers three fourths of the Earth’s surface.
Bay (n): A body of water forming an indentation of the shoreline larger than a cove but smaller than a gulf.
Gulf (n): A portion of an ocean or sea partly enclosed by land.
Cape (n): A piece of land jutting into the sea or some other large body of water; point, headland.
Channel (n): The bed where a natural stream of water runs. 2) The deeper parts of a river, harbor, strait.
Lake (n): A large body of water completely surrounded by land.
Mesa (n): A land formation less extensive than a plateau, having steep walls and relatively flat top; common in arid and semiarid parts of the south western U.S. and Mexico.
Mountain (n): A natural elevation of land rising more or less abruptly to a summit, and attaining altitude greater than that of a hill.
Valley (n): An elongated depression of the Earth’s surface usually between ranges of hills or mountains.
Peninsula (n): An area of land almost completely surrounded by water except for an Isthmus connecting it with a mainland.
Isthmus (n): A narrow strip of land, bordered on both sides by water, connecting two larger bodies of land. [Isles (plural)]
Plain (n): An area of land not significantly higher than adjacent areas and with
relatively minor differences in elevation, commonly less than 500ft (150m) within their area.
River (n): A natural stream of water of fairly large size flowing in a definite course or channel, or series of divering and convering channels.
Tributary (n): A stream that flows to a large stream or other body of water.
Delta (n): A nearly flat plain of alluvial, often triangular deposit between diverging branches of the mouth of a river.
Sea (n): The salt water that covers the greater part of the Earth’s surface.
Strait (n): A narrow passage of water connecting two larger bodies of water.
Canal (n): An artificial waterway for navigation, irritation ,etc.