convergency vs converge

convergency is a noun but converge is not a noun.

Word	Noun	Adjective	Verb	Adverb
convergency	Yes	No	No	No
converge	No	No	Yes	No

convergency (noun)	converge (noun)
the act of converging (coming closer)
the approach of an infinite series to a finite limit

convergency (verb)	converge (verb)
	come together so as to form a single product
	move or draw together at a certain location
	be adjacent or come together
	approach a limit as the number of terms increases without limit