holdover

Something left behind, saved or remaining from an earlier time.

“That policy is a holdover from days of punch card data entry.”

The distance (at target) by which a rifle scope is aimed higher than the intended point of impact in order to compensate for bullet drop over the distance to the target.

“This rangefinder not only measures the distance to the target, but also provides a digital readout of the inches of holdover at that distance.”