n The act of moving or revolving around, or as in a circle or orbit; a revolution; as, the periodical circuit of the earth around the sun.
n A regular or appointed journeying from place to place in the exercise of one's calling, as of a judge, or a preacher.
n (legal) A certain division of a state or country, established by law for a judge or judges to visit, for the administration of justice.
n By analogy to the proceeding three, a set of theaters among which the same acts circulate; especially common in the heyday of vaudeville.