synchrony vs synchronous

synchrony is a noun but synchronous is not a noun.

Word	Noun	Adjective	Verb	Adverb
synchrony	Yes	No	No	No
synchronous	No	Yes	No	No

synchrony (noun)	synchronous (noun)
the relation that exists when things occur at the same time

synchrony (adjective)	synchronous (adjective)
	occurring or existing at the same time or having the same period or phase
	(digital communication) pertaining to a transmission technique that requires a common clock signal (a timing reference) between the communicating devices in order to coordinate their transmissions