twosome

1. not comparableBeing or constituting a pair; two.
2. not comparableTwofold; double.

   Synonyms: twissel

3. not comparablePerformed by two individuals.

   a twosome dance

plural twosomes

1. A group of two; a pair; a couple; a group of two distinct individuals or components.

   1 more example

   And I was tooling along a mossy path with the brow a bit wet with honest sweat, when there came to my ears the unmistakable sound of somebody reading poetry to someone, and the next moment I found myself confronting a mixed twosome who had dropped anchor beneath a shady tree in what is known as a leafy glade.

   1960, P. G. Wodehouse, Jeeves in the Offing, chapter III

   Synonyms: duet

2. A dance for two people.