consistency vs coherency

consistency and coherency both are nouns.

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

As nouns, coherency is a hypernym of consistency; that is, coherency is a word with a broader meaning than consistency:

Other hypernyms of consistency include coherence, cohesion, cohesiveness.

consistency (noun)	coherency (noun)
the property of holding together and retaining its shape	logical and orderly and consistent relation of parts
(logic) an attribute of a logical system that is so constituted that none of the propositions deducible from the axioms contradict one another	the state of cohering or sticking together
a harmonious uniformity or agreement among things or parts
logical coherence and accordance with the facts