The Oxford Thesaurus An A-Z Dictionary of Synonyms - circuit n.

1) compass, circumference, perimeter, periphery, girth, border, boundary, edge, limit, ambit, margin, outline, confine(s) , bound, pale: The circuit of the area amounts to 72 miles. 2) round, tour, ambit, circle, orbit, course, lap: The rider completed the circuit of the ranch, mending the fence as he went.