let up
1．lessen in intensity；diminish；slacken off 减少；放松
It's raining hard as ever．It's not letting up at all．雨下得还是那么大，根本没有小下来。
Harry never lets up for a minute．哈利一刻也没有松劲。
2．stop working 停止；停止做
Let up for a few minutes．You can't work hard all day．歇一会吧，你不能整天苦干。
The doctor has been working for fifty hours without letting up．医生已马不停蹄地连续工作了50小时。
3．become easier，kinder or less strict 宽容（常与on连用）
Let up on Jane．She is sick．对简宽容点，她病了。
Let up on him．He didn't mean any harm．饶了他吧，他并没有什么恶意。