drinking fountain vs water fountain

drinking fountain and water fountain both are nouns.

Word	Noun	Adjective	Verb	Adverb
drinking fountain	Yes	No	No	No
water fountain	Yes	No	No	No

As nouns, drinking fountain and water fountain are synonyms defined as:

drinking fountain and water fountain: a public fountain to provide a jet of drinking water

Other synonyms of drinking fountain include bubbler.

drinking fountain (noun)	water fountain (noun)
a public fountain to provide a jet of drinking water	a public fountain to provide a jet of drinking water