arc

1. N-COUNT An arc is a smoothly curving line or movement. 弧线; 弧线运动

The helicopter made a slow arc, passing over the mound but not stopping. 这架直升飞机做了一个缓慢的弧线运行，飞过那座小丘，但没停下来。

2. N-COUNT In geometry, an arc is a part of the line that forms the outside of a circle. 弧[技术]