passing water vs making water

passing water and making water both are nouns.

Word	Noun	Adjective	Verb	Adverb
passing water	Yes	No	No	No
making water	Yes	No	No	No

As nouns, passing water and making water are synonyms defined as:

Other synonyms of passing water include leak, wetting.

passing water (noun)	making water (noun)
a euphemism for urination	a euphemism for urination