appositional vs apposition

appositional is not a noun while apposition is a noun.

Word	Noun	Adjective	Verb	Adverb
appositional	No	Yes	No	No
apposition	Yes	No	No	No

appositional (noun)	apposition (noun)
	the act of positioning close together (or side by side)
	(biology) growth in the thickness of a cell wall by the deposit of successive layers of material
	a grammatical relation between a word and a noun phrase that follows

appositional (adjective)	apposition (adjective)
relating to or being in apposition