could be translated as controlled group sword practice.
Most sword styles practice
kumi-tachi as a pre-arranged sword partner exercise. It teaches students how to approach each other, how to keep the right striking distance, how to learn blade control, foot-work, posture and focus. Most importantly, it teaches the student how to read an opponent’s body-language so as to strike before the opponent can strike or to be able to deflect an incoming attack and immediately counter strike.
At an advanced stage
kumi-tachi is practiced by stringing together sword attack and counter moves in rapid succession that can give an impression of a real sword fight. A similar approach can be seen in stage or movie fencing chanbarra.