Foursome/ˈfɔːrsəm/ Definition 1 of 3Pro Tip 1/3Social Context Often used to describe groups socializing or working together, like friends or colleagues. The new interns quickly became a tight-knit foursome. Pro Tip 2/3Fixed Number Specifically refers to four entities, no more, no less; important in coordinating activities. Her dinner tables are set up for foursomes only. Pro Tip 3/3Balance and Equality Suggests a sense of balance or equality among the group members, like in card games or sports. We need another player to complete our bridge foursome.