Unconcerned means not worried, not bothered, or not interested in something that might worry others. When you're unconcerned about an upcoming spelling test because you've studied thoroughly, you feel calm and confident rather than anxious.

The word describes a state of not caring or not feeling troubled. A cat might seem completely unconcerned while a thunderstorm rages outside, calmly grooming itself as if nothing were happening. A student who hasn't studied might act unconcerned about tomorrow's exam, either because they genuinely don't care or because they're pretending not to be nervous.

Sometimes being unconcerned can be helpful: worrying about things you can't control, like whether it will rain during recess, usually doesn't change what happens. Other times, being unconcerned can be a problem. If you're unconcerned about turning in homework on time, you might end up with poor grades. If a ship captain were unconcerned about storm warnings, the crew could be in danger.

The word often appears with “about” or “with”: unconcerned about the noise, unconcerned with others' opinions. Someone who is unconcerned has decided, for better or worse, that something simply doesn't matter enough to occupy their thoughts.