急流勇退的英文：
to go (or to leave) while the going is good; to resolutely retire at the height of one's official career; to retire when one has ridden the crest of success

参考例句：

Retreat bravely—i. e. draw back wisely in face of overwhelming odds
急流勇退

leave是什么意思：
v. 离开；出发；舍弃；脱离；辞去；遗忘；听任；留下；交托
n. 休假；许可；辞别

To leave;vacate.
离开；撤出

I leave that to you.
这都留给你啦。

Leaves die, fall, and shrivel.
叶子凋零、飘落枯萎了。

going是什么意思：
n. 出发；进展情况；地面状况
adj. 流行的；进行中的；现存的
v. go的现在分词

Go to the back room. Go!
到后面的房间，走！

Have a go, please!
请试一下吧！

go on [have] a splurge
挥霍金钱,乱花钱

good是什么意思：
adj. 好的；令人满意的；愉快的；仁慈的
n. 好处；利益；有道德的人或事
adv. 好

A good appetite is a good sauce
饥不择食

The prompt goods have good qualities.
当场付款的物品质量不错。

Be not simply good; be good for something.
不要单纯做个好人，还要做个能派上用场的人。