To curl means to form or bend into a spiral or curved shape, like how a cat curls up into a ball when sleeping, or how ribbon curls when you run scissors along it. Hair naturally curls for some people, forming ringlets or waves instead of hanging straight. Smoke curls upward from a candle in wispy spirals. When you curl your fingers, you bend them inward toward your palm.

The word also describes a specific exercise where you lift weights by bending your arm at the elbow, bringing your hand toward your shoulder. Weightlifters do bicep curls to strengthen their arms.

In sports, curling is a game played on ice where players slide heavy granite stones toward a target, using brooms to sweep the ice and control the stone's path. The stones curl or curve as they glide.

You might curl up with a good book, meaning you settle into a comfortable, tucked position for reading. On a cold morning, you might find yourself curled up under warm blankets, your body naturally forming a cozy, rounded shape that keeps you warm. When something makes you uncomfortable, you might say it makes your toes curl, describing that instinctive tightening feeling.