uncaring
Not showing care, kindness, or concern for others.
Uncaring describes someone who doesn't show concern or compassion for others' feelings or needs. An uncaring person might walk past a classmate who dropped their books without stopping to help, or ignore a friend who's obviously upset about something.
The word suggests a real absence of empathy or consideration that goes beyond being momentarily distracted or busy. When a teacher seems uncaring, students feel like their questions and struggles don't matter. When a friend acts uncaring about something important to you, it hurts because they're not acknowledging what you're going through.
You might describe a policy or system as uncaring when it treats people coldly or mechanically, without considering their individual situations. An uncaring response to someone's problem might be a shrug or a “that's not my problem” attitude.
The opposite of uncaring is being caring: showing genuine interest in others' well-being, noticing when something's wrong, and taking the time to help or comfort.