make up a foursome
1. To constitute a group or team of four people or things. The drummer, bassist, guitar player and singer make up a foursome of some of the most talented musicians in the industry.
2. To bring four people or things together into a group or team. We need to make up a foursome if we want to enter a team into the tournament. Most of the wedding guests are going to be couples, so it should be easy enough to make up foursomes for the reception dinner.
make up a foursome
to assemble into a team of four people. We have three people now. Who can we get to make up a foursome? Let's make up a foursome and play bridge.