1. A competition or sporting event that is open to all participants regardless of their professional status, ranking, or membership in an organization
The tennis championship is an open tournament where both amateur and professional players can compete.
O campeonato de tênis é um torneio aberto onde jogadores amadores e profissionais podem competir.
2. An event that does not have restrictions on who may enter or participate
The golf open tournament attracted participants from around the world.
O torneio aberto de golfe atraiu participantes de todo o mundo.