tonic water vs quinine water

tonic water and quinine water both are nouns.

Word	Noun	Adjective	Verb	Adverb
tonic water	Yes	No	No	No
quinine water	Yes	No	No	No

As nouns, tonic water and quinine water are synonyms defined as:

tonic water and quinine water: lime- or lemon-flavored carbonated water containing quinine

Other synonyms of tonic water include tonic.

tonic water (noun)	quinine water (noun)
lime- or lemon-flavored carbonated water containing quinine	lime- or lemon-flavored carbonated water containing quinine