a relatively thin sheetlike expanse or region lying over or under another

the part of the earth's surface covered with water (such as a river or lake or ocean)

the solid part of the earth consisting of the crust and outer mantle

an open or empty space in or between things

the bottom surface of any lake or other body of water

the lower inside surface of any hollow structure

the part of the earth's surface covered with water (such as a river or lake or ocean)

the solid part of the earth consisting of the crust and outer mantle

an open or empty space in or between things