coetaneous vs synchronous

coetaneous and synchronous both are adjectives.

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

coetaneous (adjective)	synchronous (adjective)
of the same period	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