segmental vs linguistics

segmental is not a noun while linguistics is a noun.

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

segmental (noun)	linguistics (noun)
	the scientific study of language
	the humanistic study of language and literature

segmental (adjective)	linguistics (adjective)
having the body divided into successive metameres or segments, as in earthworms or lobsters
divided or organized into speech segments or isolable speech sounds