Definition of: waterglass

(wô′tər·glas′, -gläs′, wot′ər-) noun
1. A waterclock; clepsydra.
2. A glass–bottomed tube or box for examining objects lying or moving under water.
3. A substance composed of sodium silicate, potassium silicate, or both, soluble in hot water: used in preserving eggs, as a facing for walls, etc.
4. A water gage on a steam boiler, etc.
5. A vessel for holding water; a drinking glass.