linguistics vs synsemantic

linguistics is a noun but synsemantic is not a noun.

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

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

linguistics (adjective)	synsemantic (adjective)
	of a word or phrase meaningful only when it occurs in the company of other words