big top
noun
Definitions
A circus tent, especially the largest in a given circus, where the central attractions take place.
Example: As a trapeze performer, she generally worked in the big top, but due to her injury, she was stuck working concession.
(by extension) The circus; the circus lifestyle.
Example: He had been a big top performer in his youth, but in a twist of fate he had run away to become an investment banker.