water glass

noun5

1. •
   A drinking vessel intended or used for water.

   • She asked the server to refill her water glass.
2. •
   Any 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
3. •
   An 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.
4. •
   A water gauge for a steam boiler.
5. •
   A water clock.