1. a drinking glass; tumbler.
2. a glass container for holding water, as for growing bulbs, plants, or the like.
3. a glass tube used to indicate water level, as in a boiler.
4. a device for observing objects beneath the surface of the water, consisting essentially of an open tube or box with a glass bottom.
5. See sodium silicate. Also,wa'ter•glass".
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.