water glass vs water gage

water glass and water gage both are nouns.

Word	Noun	Adjective	Verb	Adverb
water glass	Yes	No	No	No
water gage	Yes	No	No	No

As nouns, water glass and water gage are synonyms defined as:

water glass and water gage: gauge for indicating the level of water in e.g. a tank or boiler or reservoir

Other synonyms of water glass include water gauge.

water glass (noun)	water gage (noun)
a glass for drinking water	gauge for indicating the level of water in e.g. a tank or boiler or reservoir
gauge for indicating the level of water in e.g. a tank or boiler or reservoir
clock that measures time by the escape of water
a viscous glass consisting of sodium silicate in solution; used as a cement or as a protective coating and to preserve eggs