concurrence vs concurrency

concurrence and concurrency both are nouns.

Word	Noun	Adjective	Verb	Adverb
concurrence	Yes	No	No	No
concurrency	Yes	No	No	No

As nouns, concurrence and concurrency are synonyms defined as:

concurrence and concurrency: acting together, as agents or circumstances or events

As nouns, concurrence and concurrency are synonyms defined as:

concurrence (noun)	concurrency (noun)
acting together, as agents or circumstances or events	acting together, as agents or circumstances or events
the temporal property of two things happening at the same time	agreement of results or opinions
agreement of results or opinions
a state of cooperation