unfeeling; cold-blooded; callous

cruel and unfeeling; describes someone who is cold-hearted or pitiless

completely lacking any feeling, loyalty, or sense of justice; heartless and merciless

To suddenly become cold or hostile toward someone; to turn ruthlessly against a friend without any regard for past feelings or kindness.

Flowing water is indifferent to human emotion, meaning that things go their own way independently of man's will or that time passes relentlessly.

(idiom) describes the relentless and destructive nature of fire and water disasters

(idiom) strictly impartial and fair; showing no favoritism or mercy; incorruptible

to turn against someone and forget previous kindness or friendship; to suddenly become cold and heartless

to suddenly turn one's face against someone and show no mercy; to forget someone's past kindness or help and become hostile

listless and indifferent; feeling bored and depressed, often as a result of being distracted by emotional worries or missing someone

to act strictly on the basis of logic or principle while ignoring personal relationships or feelings; to be fair yet showing no mercy or being unreasonably stiff

men are not like trees or grass, how can they be without feelings; everyone has feelings and emotions

literally meaning "falling flowers have feelings, but the flowing water has none"; used to describe a situation where one person is in love or interested, but the other remains indifferent

to turn one's face against someone and show no mercy; to suddenly turn cold or heartless toward someone one previously knew well