Your chin is the rounded or pointed part of your face below your mouth, where your lower jaw comes forward. Run your finger down from your bottom lip and you'll feel where your face juts out slightly: that's your chin.

People have many expressions involving chins. When someone faces difficulty bravely, we say they “keep their chin up.” A superhero or determined athlete might thrust their chin forward as a sign of confidence. When someone rests their chin on their hand while thinking, it shows they're concentrating deeply.

Humans have especially prominent chins compared with other primates. Scientists still debate why humans evolved this distinctive feature, though it likely relates to how our jaws and faces developed over millions of years.

In everyday life, your chin gets mentioned more than you might expect. A baseball player might wear a chin strap to keep their helmet secure. Someone deep in thought might stroke their chin thoughtfully. And when you're learning to swim, instructors often remind you to keep your chin at the water's surface. The phrase “take it on the chin” means to face a setback or defeat with courage.