负心的英文：
ungrateful; heartless

参考例句：

Her singer had betrayed her, had given her away, as we say nowadays.
她的诗人对她负心，像我们现在所说的，把她抛弃。

She might feel how sharper than a serpent's tooth it was to have a thankless child
让她也知道知道有个负心的孩子要比挨毒蛇的牙齿咬还要痛苦。

ungrateful是什么意思：
adj. 不感激的，忘恩负义的；令人不快的

ungrateful adj.
忘恩负义的；使人不愉快的；徒劳的；讨厌的

Lack of gratitude; ungratefulness.
没有感谢之意的；忘恩负义的

It was for your sake I came; and it will be wickedly ungrateful if you refuse.
为了你的缘故，我才来;如果你不肯的话，那太忘恩负义了。

Ingratitude is a kind of weakness and clever men are not ungrateful.
忘恩负义是一种软弱的表现，明智的人不会忘记别人的恩德。

I will not perform the ungrateful task of comparing cases of failure- Abraham Lincoln.
我再也不会做这种让人讨厌的比较失败案例的任务了-亚伯拉罕·林肯。

heartless是什么意思：
a. 无情的,无勇气的

It was heartless of you to leave without saying good - bye.
你不告而别实在太狠心了。

The heartless witch cast a spell on the poor little girl.
狠心的女巫对孤苦无助的小女孩施发妖术。

Phileas Fogg, though brave and gallant, must be, he thought, quite heartless
而斐利亚·福克心里显然是只想到英勇果敢地，而不是深情脉脉地尽自己的义务。

Heartless circumstance could not leave entire gabriel's happiness of this morning
无情的命运并没有离开今天早晨感到十分快乐的加布里埃尔。

The heartless hip analysis of crime is.a part of my life and my mentation(Scott Turow)
对犯罪行为进行冷酷的分析是…我生活和心理活动的一部分(斯科特·图罗)