water glass

plural water glasses

1. countableuncountableA drinking vessel intended or used for water.

   She asked the server to refill her water glass.

2. countableuncountablechemistryAny of various water-soluble silicate compounds, especially when occurring in dissolved, jelly-like form.

   No; what I felt was a sort of glazed numbness, as if I were suspended in some thin, transparent stuff, like one of the eggs my mother used to preserve in waterglass when I was a child.

   1993, John Banville, Ghosts

   Synonyms: liquid glass, sodium silicate, soluble glass

3. countableuncountableA water gauge for a steam boiler.
4. countableuncountableAn instrument consisting of an open box or tube with a glass bottom, used for examining objects in the water, as upon the sea bottom in shallow places.
5. countableuncountableA water clock.