Synonyms for Duet (same or very similar meaning)
WordNet sense 1 (two items of the same kind):
brace, couple, couplet, duo, pair, span, twain, twosome, yoke, distich, duad, dyadWordNet sense 2 (two performers or singers who perform together):
duetteWordNet sense 3 ((ballet) a dance for two people (usually a ballerina and a danseur noble)):
pas de deuxFrom the ODE community, based on WordNetadd/edit