duad vs duet

duad and duet both are nouns.

Word	Noun	Adjective	Verb	Adverb
duad	Yes	No	No	No
duet	Yes	No	No	No

As nouns, duad and duet are synonyms defined as:

Other synonyms of duad include brace, couple, couplet, distich, duo, dyad, pair, span, twain, twosome, yoke.

duad (noun)	duet (noun)
two items of the same kind	(ballet) a dance for two people (usually a ballerina and a danseur noble)
	a musical composition for two performers
	a pair who associate with one another
	two performers or singers who perform together
	two items of the same kind