mestiza vs woman

mestiza and woman both are nouns.

Word	Noun	Adjective	Verb	Adverb
mestiza	Yes	No	No	No
woman	Yes	No	No	No

As nouns, woman is a hypernym of mestiza; that is, woman is a word with a broader meaning than mestiza:

mestiza: a woman of mixed racial ancestry (especially mixed European and Native American ancestry)
woman: an adult female person (as opposed to a man)

Other hypernyms of mestiza include adult female.

mestiza (noun)	woman (noun)
a woman of mixed racial ancestry (especially mixed European and Native American ancestry)	women as a class
	an adult female person (as opposed to a man)
	a female person who plays a significant role (wife or mistress or girlfriend) in the life of a particular man