run-up
n
1
(a) (of a bowler in cricket, an athlete, etc) running in order to gain speed before releasing the ball, jumping, etc （指板球的投球手、 田径运动员等的）助跑
a fast, smooth, short, etc run-up 快速的、 稳健的、 短距离的...助跑.
(b) distance run in this way 助跑距离
Pole vaulters need long run-ups. 撑竿跳需要长距离助跑.
2 ~ (to sth) period of time leading to an event （事件的）准备时期
the run-up to the election 选举前的酝酿时期.