definition of
duo

[1] #1 duo n. [couple, pair, twosome, twain, brace, span, yoke, couplet, distich, duet, dyad, duad] two items of the same kind. wn

[2] #2 duo n. [duet, duette] two performers or singers who perform together. wn

[3] #3 duo n. [couple, twosome, duet] a pair who associate with one another; "the engaged couple"; "an inseparable twosome". wn

[4] #4 duo n. [duet, duette] a musical composition for two performers. wn