When a group — whether it's a team, club, class, or Scout troop — gives its members a sense of cohesion and support, it has esprit de corps.
If you've ever been on a sports team that had great morale and team spirit, you've experienced esprit de corps. The term is French, and it literally means "the spirit of the body," with body in this case meaning "group." Originally, esprit de corps was used to describe the morale of military troops. Pronounce it with a hint of a French accent: "espree de core."