grammar vs unrestricted

grammar is a noun but unrestricted is not a noun.

Word	Noun	Adjective	Verb	Adverb
grammar	Yes	No	No	No
unrestricted	No	Yes	No	No

grammar (noun)	unrestricted (noun)
the branch of linguistics that deals with syntax and morphology (and sometimes also deals with semantics)

grammar (adjective)	unrestricted (adjective)
	not subject to or subjected to restriction
	free of restrictions on conduct
	not restricted or exclusive
	never having had security classification
	not restricted or modified in meaning