noun
trio
TREE-oh/ˈtriːəʊ/
A set of three related participants.
The trio of musicians performs together without other players.

Etymology
Trio first named a musical composition for three solo parts. This musical grouping broadened into the general meaning of three people or things considered together.
In context
Then we became a trio – Matti, Ya'akov Arnon and myself – and we functioned in harmony
More examples
- The jazz trio plays here every Friday.
- A trio of paintings hangs above the couch.
- The students work in trios to solve the puzzle.
Forms
trio · trios
Similar words
- threesome
- Usually refers to three people doing an activity together.
- triad
- Often names three closely connected elements in a structured system.