mixed-blood vs Metis

mixed-blood and Metis both are nouns.

Word	Noun	Adjective	Verb	Adverb
mixed-blood	Yes	No	No	No
Metis	Yes	No	No	No

As nouns, Metis is a hyponym of mixed-blood; that is, Metis is a word with a more specific, narrower meaning than mixed-blood:

mixed-blood: a person whose ancestors belonged to two or more racial groups
Metis: a person in western Canada who is of Caucasian and American Indian ancestry

Other hyponyms of mixed-blood include mulatto, quadroon, octoroon, half-caste.

mixed-blood (noun)	Metis (noun)
a person whose ancestors belonged to two or more racial groups	a person in western Canada who is of Caucasian and American Indian ancestry