retard

retard the march of an army

to retard the attacks of old age

This application of hydraulics led Sir George Dowty to develop the wagon retarder system, which comprised small hydraulic rams mounted inside the rail. These rams could simply retard a wagon, or both retard and 'boost' or speed up a wagon by hydraulic pressure.

Some years it [The River Nile] hath also retarded, and come far later than usually it was expected