remorse

悔恨、懊悔、自責

He showed no remorse for the pain he had caused.

他對自己造成的傷害毫無悔意。

良心不安、愧疚

She was kept awake by remorse over the harsh words.

她因為那些重話而良心不安，整夜難以入睡。

毫不留情、毫無悔意

The gang robbed the elderly couple without remorse.

那幫人毫不留情地洗劫了那對老夫婦。