A fender is a curved metal panel that covers the wheel of a car, truck, or bicycle. If you look at a car from the side, the fenders are those rounded pieces that arch over each tire. They protect the body of the vehicle from rocks, mud, and water that the spinning wheels kick up. Without fenders, your car would get splattered with dirt and debris every time you drove through a puddle.

On bicycles, fenders are especially useful in wet weather, keeping that stripe of muddy water off your back as you ride.

A fender can also mean something that protects boats from damage. Boat fenders are cushions that hang over the side of a boat to keep it from scraping against a dock or another boat. When a boat pulls into a harbor, sailors lower fenders to protect the hull.

You might hear about a fender bender, which is a minor car accident where vehicles bump into each other at low speed, usually just denting the fenders rather than causing serious damage.