nigga vs Black person

nigga and Black person both are nouns.

Word	Noun	Adjective	Verb	Adverb
nigga	Yes	No	No	No
Black person	Yes	No	No	No

As nouns, Black person is a hypernym of nigga; that is, Black person is a word with a broader meaning than nigga:

nigga: (ethnic slur) extremely offensive name for a Black person
Black person: a person with dark skin who comes from Africa (or whose ancestors came from Africa)

Other hypernyms of nigga include African-American, Black, Negro, Negroid, blackamoor.

nigga (noun)	Black person (noun)
(ethnic slur) extremely offensive name for a Black person	a person with dark skin who comes from Africa (or whose ancestors came from Africa)