A bumper is a bar or cushion attached to the front and back of a car or truck, designed to absorb impact during minor collisions. When a driver accidentally taps another car in a parking lot, the bumpers take most of the hit, protecting the vehicle's body and the people inside. Modern bumpers contain foam, plastic, and sometimes metal that compress on impact, like a shock absorber.

Before bumpers, even gentle collisions could cause serious damage to vehicles. Now, bumpers help minimize repair costs and injuries from low-speed accidents.

You'll also hear bumper used as an adjective to describe something unusually large or abundant, as in a bumper crop of tomatoes when a farm produces far more than expected. A bumper crowd means an especially large turnout.

In bowling, some alleys have bumpers that pop up in the gutters to keep the ball on the lane, helpful for younger players learning the game. The concept is similar: something that prevents going off course or cushions against mistakes.