Insensitive means not noticing or not caring about other people's feelings. When someone is insensitive, they might say or do things that hurt others without realizing it, or sometimes without seeming to care.

Imagine a classmate bragging loudly about their perfect test score right next to someone who just failed. That's insensitive because they're not thinking about how their words might make the other person feel worse. Or picture someone making jokes about a topic that genuinely upsets their friend. Even if they think it's funny, that insensitivity shows they're not paying attention to how their friend reacts.

Being insensitive is different from being deliberately mean. Mean people want to hurt others, while insensitive people often just aren't paying attention to the feelings around them. Someone might be insensitive because they're distracted, self-centered, or simply haven't learned to notice emotional cues yet.

The opposite is being sensitive, which means being aware of and responsive to others' feelings. You can also be insensitive to physical sensations: if your foot falls asleep, it becomes temporarily insensitive to touch. But most often, the word describes someone who needs to develop more awareness of how their actions affect the people around them, and to show more care.