nigger vs nigga

nigger and nigga both are nouns.

Word	Noun	Adjective	Verb	Adverb
nigger	Yes	No	No	No
nigga	Yes	No	No	No

As nouns, nigger and nigga are synonyms defined as:

nigger and nigga: (ethnic slur) extremely offensive name for a Black person

Other synonyms of nigger include jigaboo, nigra.

nigger (noun)	nigga (noun)
(ethnic slur) extremely offensive name for a Black person	(ethnic slur) extremely offensive name for a Black person