xīn​gān

conscience

心肝 xīn​gān
conscience noun
humanity or moral heart, typically used in negative constructions to denote heartlessness

Doing something like that shows you are truly heartless.

darling noun
a beloved person; a term of endearment often used for a child or lover

She is the apple of her parents' eye.

Frequency

Movie subtitles
2.21 per million appears in 1% of films
Written text
2.45 per million

Sources

Definitions
CC-CEDICT