trio

Etymology

PIE word *tréyes 1715-25; borrowing from Italian trio.

noun

1. A group of three people or things.
   I'm cooking crab cakes with arugula and mayonnaise, griddled lamb with rosemary potatoes and buttered spinach, then a trio of desserts. 2015, Kate Hardy, Bachelor at Her Bidding
   These are exciting times for England and particularly for this group. Six of this side won the Under-17s European Championship in 2014 and the attacking trio from Everton and Liverpool – Ademola Lookman, Dominic Solanke and Calvert-Lewin – had an excellent tournament. June 11, 2017, Ben Fisher, “England seal Under-20 World Cup glory as Dominic Calvert-Lewin strikes”, in the Guardian
2. A group of three musicians.
3. (music) A piece of music written for three musicians.
   I love his music, but it is a bit disconcerting to realize that you could die in extreme old age and still only be familiar with a mere handful of the baryton trios. 2013, Simon Winder, Danubia, Picador, published 2014, page 281
4. (music) A passage in the middle of a minuet, frequently in a different key.
5. Any cocktail made with a spirit, a liqueur, and a creamy ingredient.