Not caring about how other people feel — cold, hard, showing no kindness when kindness is called for. It is a judgement, and quite a strong one. If you call someone unfeeling, you are saying something is missing in them, not just that they were rude once. It is used most about words and actions: an unfeeling remark, an unfeeling letter, an unfeeling response to bad news. And it is often used about institutions rather than people — an unfeeling bureaucracy, an unfeeling system — where the point is that nobody in the machine seems to notice a human being is suffering. There is a second, older and more physical meaning: without any physical sensation, numb. In old writing you meet "unfeeling stone," "unfeeling flesh" — matter that cannot feel because it is not alive. Both meanings run through the same idea: nothing registers. In everyday modern speech, people more often say heartless, cold, or insensitive; unfeeling sounds a shade more literary, and a shade sadder.