D is for Drift

Something is drifting if it is being gently carried along by currents in air or water with no particular direction. The leaf in the picture is drifting on a lake.
A drift is a pile of snow that has been blown by the wind. Snow drifts often form along fences, walls, or hills where the wind slows down and drops the snow. Snow drifts can become much deeper than the snow that originally fell. In strong winds, drifting snow can block roads, cover paths, and build up in large mounds.