A pothole is a hole or depression that forms in a paved road surface, usually when water seeps into cracks in the pavement, freezes, expands, and then breaks apart the road material. When cars and trucks drive over these weakened spots repeatedly, chunks of pavement break away, leaving a bowl-shaped hole.

Potholes range from small divots to craters big enough to damage a car's tires or suspension. They're especially common in places with cold winters, where the cycle of freezing and thawing tears roads apart. Cities and towns work to fill potholes with fresh asphalt, but new ones keep appearing, which is why you might see road crews patching the same streets every spring.

Hitting a pothole at high speed can be jarring and expensive. Drivers learn to watch the road ahead and steer around potholes when possible. The word has also become a metaphor: someone might describe an unexpected problem in a plan as a pothole along the way, meaning a rough spot that slows progress but can be navigated around or fixed.