喪盡天良

丧尽天良
sàngjìntiānliáng
devoid of conscience (idiom); utterly heartless

CEDICT

to be utterly devoid of conscience; to be extremely vicious and evil

Wiktionary

形容泯滅人性極為惡毒

重編國語辭典

喪失所有良知

維基詞典

Entry Composition