Teamfight:

A teamfight is a coordinated battle in which most or all heroes from both teams clash in the same area at the same time. In Dota 2, teamfights often decide objectives such as towers, Roshan, and high ground, because winning one can lead to several map gains at once.

The term is used to describe both the fight itself and the heroes or lineups that are strong in grouped engagements, such as heroes with area damage, crowd control, or teamwide saving abilities.