water glass vs water gauge

water glass and water gauge both are nouns.

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

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

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

Other synonyms of water glass include water gage.

water glass (noun)	water gauge (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