A brake is a device that slows down or stops something that's moving. When you squeeze the hand brakes on your bicycle, rubber pads press against the wheels to create friction, which slows you down. Cars have brakes that work when you press the pedal, using hydraulic pressure to stop the wheels from turning.

The word can also mean to slow down or stop, as when you brake before a stop sign or brake hard to avoid hitting something. A driver might brake suddenly if a ball rolls into the street.

Don't confuse brake with break, which means to damage or destroy something. You brake your bike to slow down, but you break your bike if you crash it into a tree. Here's an easy way to remember: brakes help you not break things.