racetrack

n. 跑道(共振加速器中粒子轨道)

One complete round or circuit, especially of a racetrack.

一圈跑道完整封闭的一圈，尤指跑道

A position at a distance from the inside or center, as of a playing field or racetrack.

界外，外侧位置远离，如运动场或跑道的内部或中心的位置