A small, movable auxiliary graduated scale attached parallel to a main graduated scale, calibrated to indicate fractional parts of the subdivisions of the larger scale, and used on certain precision instruments to increase accuracy in measurement.

• 游标，游标尺一种平行附于主标尺上的可移动小型辅助标尺，被标定用来指示较大刻度的再分刻度的分数部分，并且被用于某些精密仪器上来增加测量的精确度