心狠手辣的英文：
callous and cruel; ruthless; relentless

参考例句：

The spy was cruel and evil.
这个间谍心狠手辣。

He became appalled at unsavory tricks
如此心狠手辣的手段，使他惊呆了。

He became appalled at unsavory tricks.
如此心狠手辣的手段，使他惊呆了。

His father had chosen another bride for him, whose face was as ugly as her heart was wicked.
王子的父亲给他挑选了另一位新娘，这位新娘不仅奇丑无比，而且心狠手辣。

callous是什么意思：
adj. 无情的，冷漠的；硬结的，长茧的

He reads the callous skin of her hands.
他发现她的手很粗糙。

We usually have more callous on the left hand.
我们的左手经常会磨出硬茧。

Some of us backstairs crowd thought he was callous about Missy.
我们当中的一些仆人认为，他对米丝太无情。

cruel是什么意思：
adj. 残忍的；残酷的；令人极痛苦的；刻毒伤人的；惨痛的

Cowards are cruel
懦夫不仁

How can fate be this cruel?
命运为何如此残酷?

This is a cruel joke at my expense.
以我为代价的残酷笑话。

ruthless是什么意思：
adj. 无情的；坚决的

He was utterly ruthless in his determination to succeed.
他下定决心争取成功。

They represented a ruthless and illegitimate regime that could not remain forever.
他们代表了一个残暴的非法政权，这样的政权是不可能长久的。

Fly: Then bite them! Be ruthless, whatever it takes. Bend them to your will!
那就咬它们！无论如何都要变得残忍些，使他们屈服！