Abstract noun; typically uncountable.
Translations
Her cold-heartedness shocked everyone in the room.
Её бессердечность шокировала всех в комнате.
His cold-heartedness became obvious at once.
Его черствость стала заметна сразу.
Definitions
the quality of being cruel, unkind, and lacking sympathy or compassion Her cold-heartedness shocked everyone in the room.