| 1. | (Chem.) See | |
| 2. | A clepsydra. | |
| 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. |
| Noun | 1. | water glass - a viscous glass consisting of sodium silicate in solution; used as a cement or as a protective coating and to preserve eggs Synonyms: sodium silicate, soluble glass |
| 2. | water glass - a glass for drinking water | |
| 3. | water glass - gauge for indicating the level of water in e.g. a tank or boiler or reservoir Synonyms: water gage, water gauge | |
| 4. | water glass - clock that measures time by the escape of water Synonyms: clepsydra, water clock |