noun (n)

• a particular environment or walk of life(noun.state)

  Synonym:
  area, domain, field, orbit, sphere
  

  source: wordnet30
• the central area of an ancient Roman amphitheater where contests and spectacles were held; especially an area that was strewn with sand(noun.location)

  source: wordnet30
• a large structure for open-air sports or entertainments(noun.artifact)

  Synonym:
  bowl, sports stadium, stadium
  

  source: wordnet30
• a playing field where sports events take place(noun.artifact)

  Synonym:
  scene of action
  

  source: wordnet30
• The area in the central part of an amphitheater, in which the gladiators fought and other shows were exhibited; -- so called because it was covered with sand.(noun)

  source: webster1913