蛮干的英文：
reckless
rash
foolhardy

参考例句：

Let them do their worst!
让他们蛮干好啦!

If you act rashly, you'll suffer for it.
蛮干是要吃苦头的。

If you act rashly, you'll suffer for it
蛮干是要吃苦头儿的。

That is the way we have to proceed,we must not rush headlong into things.
没有这条是不行的，不能蛮干。

He who will not be ruled by the rudder must be ruled by the rock.
不受制于船橹，就受制于礁石(一味蛮干，必定失败)。

The weak gain strength through effrontery and the strong grow weak because of inhibitions
弱者由于蛮干变强，强者由于克制变弱。

He relied greatly on the sagacity of the eldest, and the known impunity with which the younger passed among the savages
他完全依赖大女儿的机智以及小女儿在蛮干中的那种泰然自若的神态。

reckless是什么意思：
adj. 鲁莽的，粗心大意的，不计后果的

His tradecraft was appallingly reckless.
他的经营轻率得令人吃惊。

A reckless spender,gambler,etc
乱花钱的人、乱赌博的人

Approach love and cooking with reckless abandon.
（唯有「」「饪美食」能无节制地放纵。

rash是什么意思：
adj. 轻率的；鲁莽的；性急的
n. 皮疹；爆发

That was a rash move.
这无疑是个鲁莽的行动。

He ventured on a rash speculation.
他进行鲁莽的投机。

Students made a rash of complaints.
学生们发出一片抱怨声。

foolhardy是什么意思：
a. 愚勇的,有勇无谋的

They were very foolhardy to jump off the bus while it was still moving
公共汽车还未停定他们就跳下了车,真是太莽撞了。

One of the hostages was foolhardy enough to try to wrest the gun from the hijackers hand.
有一个人质莽撞地企图去夺劫机者手中的枪

You were very foolhardy to jump off the bus while it was still moving.
公共汽车还未停定你便跳下车，真是太莽撞了。