duet vs twosome

duet and twosome both are nouns.

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

As nouns, duet and twosome are synonyms defined as:

Other synonyms of duet include couple, duo.

As nouns, duet and twosome are synonyms defined as:

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

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