arena

(noun) a particular environment or walk of life. Synonyms: sphere, domain, area, orbit, field. Examples: "His social sphere is limited." "It was a closed area of employment." "He's out of my orbit."

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

(noun) a large structure for open-air sports or entertainments. Synonyms: stadium, bowl, sports stadium.

(noun) a playing field where sports events take place. Synonyms: scene of action.