n.

1. 【物】轨道；弹道；轨迹
   Before falling into the hoop, the basketball traveled a perfect trajectory.

   在掉入篮框之前，篮球走过一道完美的轨迹。

2. 【数】轨线；常角轨道

n.

1. the path described by a projectile flying or an object moving under the action of given forces.
2. Geometry  a curve or surface cutting a family of curves or surfaces at a constant angle.