(n.) The level of the surface of the sea; any surface on the same level with the sea.

Earth Gaea Ge Tellus Terra abri acres air air-raid shelter alluvion alluvium arable land ashes atom atomic particles billiard table biosphere body bomb shelter bombproof bones bowling green brute matter building block bunker burrow cadaver carcass carpet carrion cave chemical element clay clod component concealment constituent corpse corpus delicti cosmos couch cover covert coverture creation crowbait crust cyclone cellar dead body dead flat dead level dead man dead person decedent deck den dirt dry bones dry land dugout dust earthbound earthly element elementary particle elementary unit embalmed corpse esplanade fallout shelter fill fire flat flatland floor floor covering flooring fluvioterrestrial food for worms form foxhole freehold fundamental particle funk hole geography geophilous geosphere glebe globe grassland gravel ground hole homaloid horizontal horizontal axis horizontal fault horizontal line horizontal parallax horizontal plane horizontal projection humus hyle hypostasis lair land landholdings late lamented ledge level level line level plane lithosphere loam lodge macrocosm marginal land marl material material world materiality matter mean sea level mew mold molecule monad mortal remains mother earth mould mud mummification mummy natural world nature orb organic remains parquet parterre pave pavement paving physical world plain plane planet platform plenum prairie real estate real property region regolith relics reliquiae remains run safety zone sand sea level sea of grass shelter skeleton sod soil sphere steppe stiff storm cave storm cellar stuff subaerial deposit subastral sublunar subsoil substance substratum surfacing table tellurian telluric tenement of clay terra terra firma terrace terrain terraqueous terrene terrestrial terrestrial globe territory the blue planet the country the dead the deceased the defunct the departed the four elements the loved one this pendent world topsoil trench tunnel turf unit of being universe vale vale of tears water water level whole wide world woodland world