illative vs grammar

illative is not a noun while grammar is a noun.

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

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

illative (adjective)	grammar (adjective)
relating to or having the nature of illation or inference
expressing or preceding an inference
resembling or dependent on or arrived at by inference