water level

(noun) the level of the surface of a body of water. Synonyms: water level.

(noun) underground surface below which the ground is wholly saturated with water. Synonyms: water table, water level, groundwater level. Example: "Spring rains had raised the water table."

(noun) a line corresponding to the surface of the water when the vessel is afloat on an even keel; often painted on the hull of a ship. Synonyms: waterline, water line, water level.

(noun) a water gauge that shows the level by showing the surface of the water in a trough or U-shaped tube. Synonyms: water level.