duplet

Etymology
Mid-17th century. From.

Noun

 * 1) A group of two things.
 * 2)  A tuplet of two notes played in the time of three.
 * 3)  the set of two electrons, with antiparallel spins, in the same orbital
 * 4)  An empty box placed above the existing boxes of the beehive in order to allow the colony to expand or store additional honey.

Synonyms

 * , ; see also Thesaurus:duo