expression, godan verb (-ku)
draw an arc; describe an arc; form an arc
Used for drawing a curved line with a tool, tracing a curved path through the air, or describing something that naturally forms an arc shape.
コンパスで弧を描く。
Draw an arc with a compass.
ボールが大きな弧を描いて飛んでいった。
The ball flew in a big arc.
Compound of 弧 (arc) + を (object marker) + 描く (to draw). The expression is straightforward and transparent.