駆け足
かけあし · kakeashi · JLPT N1 · noun
fast
👟 駆け足 = 駆ける (run hard) + 足 (foot): running fast on your feet
駆ける means to run or gallop at full speed, and 足 means foot or leg. Together they name running at a fast pace, which is why drill and march commands use it for double time.
足 — top 口 (mouth/enclosure) + bottom 止 (foot)
Originally a pictograph of a leg and foot, with the upper square representing the knee or shin and the lower part 止 depicting the foot itself. It primarily means 'foot' and by extension 'sufficient' or 'enough,' a meaning shift likely from the idea of standing firmly or having a solid footing.