快速，迅速
fast
We set off at a good clip, but we gradually slowed down. 我们出发时速度很快，可是后来渐渐慢了下来。
Government investment in research has been increasing at a fast clip.
The action proceeds at a fast clip, with all the main characters introduced in the first five minutes.
Even the commuter trains move at a good clip.
The cattle headed up the hill at a good clip.
See also: clip noun (SPEED)