without mercy

详细解释:残忍地

例句：

He used to bully his secretary without mercy, but even a worm will turn and one day she walked out and left her job without even saying goodbye.他过去毫不留情地欺侮他的秘书，但是如被逼太甚，最温顺者也会反抗的，结果有一天她不辞而别了。