From Longman Dictionary of Contemporary Englishthe tennis/lecture/cabaret etc circuitthe tennis/lecture/cabaret etc circuitUSUALLYall the places that are usually visited by someone who plays tennis etc a well-known entertainer on the club circuit → circuit
Examples from the Corpus
the tennis/lecture/cabaret etc circuit• Both the Harvard and Caltech groups took their maps on the lecture circuit, giving talks at scattered conferences and universities. 