linguistics vs vocative

linguistics and vocative both are nouns.

Word	Noun	Adjective	Verb	Adverb
linguistics	Yes	No	No	No
vocative	Yes	Yes	No	No

linguistics (noun)	vocative (noun)
the scientific study of language	the case (in some inflected languages) used when the referent of the noun is being addressed
the humanistic study of language and literature

linguistics (adjective)	vocative (adjective)
	relating to a case used in some languages