a regular pattern of visits or the places visited

They first met each other on the tennis circuit (= while at different tennis competitions). 他们在网球巡回赛上首次交锋。

He was a familiar figure on the lecture circuit. 他是巡回讲学中的座上常客。

a particular area containing different courts that a judge visits

The judge had served for many years on the northeastern Circuit. 这位法官多年来供职于东北部巡回法庭。

a circuit judge 巡回法官

something shaped approximately like a circle, especially a route, path, or sports track that starts and ends in the same place

They test the car tyres on a motor racing circuit. 他们在环形赛车道上测试轮胎。

We made a leisurely circuit of the city walls. 我们悠闲地围着城墙转悠。

a closed system of wires or pipes through which electricity or liquid can flow

A defect was found in the water-cooling/electrical circuit. 在水冷回路／电路中发现了一点毛病。