adjacent vs adjacency

adjacent is not a noun while adjacency is a noun.

Word	Noun	Adjective	Verb	Adverb
adjacent	No	Yes	No	No
adjacency	Yes	No	No	No

adjacent (noun)	adjacency (noun)
	the attribute of being so near as to be touching

adjacent (adjective)	adjacency (adjective)
nearest in space or position; immediately adjoining without intervening space
having a common boundary or edge; abutting; touching
near or close to but not necessarily touching