To run down (a slope, stairs) quickly; also used figuratively for wind or water rushing downward.
子どもたちが丘を駆け下った。
The children ran down the hill.
駅の階段を駆け下って電車に飛び乗った。
He ran down the station stairs and jumped onto the train.
朝の風が谷を駆け下るように吹き抜けた。
The morning wind swept down the valley as if running downhill.