arc
n
1 part of the circumference of a circle or some other curved line 弧(圓周或其它曲線的一部分). =>illus at circle 見circle之插圖.
2 thing with this shape 弧形物
the arc of a rainbow 虹的弧形.
3 luminous electric current passing across a gap between two terminals 電弧; 弧光. arc, v (pt, pp arced , pres p arcing) [I]
form an electric arc 形成電弧; 產生弧光.