arena

noun

• An enclosed area, often outdoor, for the presentation of sporting events (sports arena) or other spectacular events; earthen area, often oval, specifically for rodeos (North America) or circular area for bullfights (especially Hispanic America).

  "A large crowd filled the seats of the arena."

• The building housing such an area; specifically, a very large, often round building, often topped with a dome, designated for indoor sporting or other major events, such as concerts.

  "The arena is grey with white beams."

• The sand-covered centre of an amphitheatre where contests were held in Ancient Rome.

  "The gladiators entered the arena."

• A realm in which events take place; an area of interest, study, behaviour, etc.

  "The company was a player in the maritime insurance arena."