mezzo vs soprano

mezzo and soprano both are nouns.

Word	Noun	Adjective	Verb	Adverb
mezzo	Yes	No	No	No
soprano	Yes	Yes	No	No

As nouns, soprano is a hypernym of mezzo; that is, soprano is a word with a broader meaning than mezzo:

mezzo (noun)	soprano (noun)
the female singing voice between contralto and soprano	the pitch range of the highest female voice
a soprano with a voice between soprano and contralto	the highest female voice; the voice of a boy before puberty
	a female singer with the highest vocal range of all the voice type

mezzo (adjective)	soprano (adjective)
	having or denoting a high range