repeat vs duplicate

repeat and duplicate both are nouns.

Word	Noun	Adjective	Verb	Adverb
repeat	Yes	No	Yes	No
duplicate	Yes	Yes	Yes	No

As verbs, repeat and duplicate are synonyms defined as:

Other synonyms of repeat include double, reduplicate, replicate.

repeat (noun)	duplicate (noun)
an event that repeats	a copy that corresponds to an original exactly
	something additional of the same kind

repeat (adjective)	duplicate (adjective)
	being two identical
	identically copied from an original

repeat (verb)	duplicate (verb)
happen or occur again	increase twofold
to say, state, or perform again	make or do or perform again
to say again or imitate	make a duplicate or duplicates of
make or do or perform again	duplicate or match
repeat an earlier theme of a composition
do over