coherency vs coherent

coherency is a noun but coherent is not a noun.

Word	Noun	Adjective	Verb	Adverb
coherency	Yes	No	No	No
coherent	No	Yes	No	No

coherency (noun)	coherent (noun)
logical and orderly and consistent relation of parts
the state of cohering or sticking together

coherency (adjective)	coherent (adjective)
	marked by an orderly, logical, and aesthetically consistent relation of parts
	(physics) of waves having a constant phase relation
	sticking together
	capable of thinking and expressing yourself in a clear and consistent manner