1. A large venue with seating for spectators, used for sports, entertainment, or other events
The concert was held in a massive arena packed with thousands of fans.
O concerto foi realizado em uma enorme arena repleta de milhares de fãs.
2. The central part of an ancient Roman amphitheater where gladiators fought
The gladiators fought in the arena before the emperor.
Os gladiadores lutaram na arena diante do imperador.
3. A sphere of activity or competition; a field or domain
She entered the political arena at a young age.
Ela entrou na arena política em uma idade jovem.