Trio
Trio , noun
[Italian, from Latin tres, tria, three: compare French trio, from the Italian. See Three.]
1.
Three, considered collectively; three in company or acting together; a set of three; three united.
The trio were well accustomed to act together, and were linked to each other by ties of mutual interest.
2.
(a) (Music) A composition for three parts or three instruments.
(b)
(Music) The secondary, or episodical, movement of a minuet or scherzo, as in a sonata or symphony, or of a march, or of various dance forms; -- not limited to three parts or instruments.