recurrence vs throwback

recurrence and throwback both are nouns.

Word	Noun	Adjective	Verb	Adverb
recurrence	Yes	No	No	No
throwback	Yes	Yes	No	No

As nouns, throwback is a hyponym of recurrence; that is, throwback is a word with a more specific, narrower meaning than recurrence:

Other hyponyms of recurrence include atavism, reversion, flashback.

recurrence (noun)	throwback (noun)
happening again (especially at regular intervals)	a reappearance of an earlier characteristic
	an organism that has the characteristics of a more primitive type of that organism

recurrence (adjective)	throwback (adjective)
	characteristic of an atavist