arena

noun

1. 1

   a playing field where sports events take place

2. 2

   a large structure for open-air sports or entertainments

3. 3

   the central area of an ancient Roman amphitheater where contests and spectacles were held; especially an area that was strewn with sand

4. 4

   a particular environment or walk of life

   his social sphere is limited

   it was a closed area of employment