What is Circus ?
Circus is (noun) 1. a travelling show, often given under a large tent, with animals, clowns and other performers We went to the circus last night. The circus is coming to town for the bank holiday weekend. 2. a busy road junction in the centre of a large town Oxford Circus is where Oxford Street crosses Regent Street. (NOTE: The plural is circuses.)
source: Easier English, Student Dictionary Upper Intermediate Level