名词

1. 弧形；弧线
An arc is a smoothly curving line or movement.

2. 弧
In geometry, an arc is a part of the line that forms the outside of a circle.

3. 成弧线；呈弧形
If something arcs in a particular direction, it makes a smoothly curving line or movement.

1. electrical conduction through a gas in an applied electric field

Synonym: dischargesparkelectric arcelectric discharge

2. a continuous portion of a circle

3. something curved in shape

Synonym: bow