无情

pitiless / ruthless / merciless / heartless

not to have / no / none / not / to lack / un- / -less

feeling / emotion / passion / situation

cruel and unfeeling (idiom)

completely lacking any feeling or sense of justice (idiom); cold and ruthless

fire and flood have no mercy (idiom)

lit. the falling flowers are yearning for love, but the heartless brook ripples on (idiom) / fig. one side is willing, yet the other one remains indifferent (usually of unrequited love)

to turn one's face against sb and show no mercy (idiom); to turn against a friend

cold-hearted; unfeeling; callous

cold-hearted / unfeeling / callous

to turn one's face against sb and show no mercy (idiom); to turn against a friend