A crater is a large, bowl-shaped hole in the ground. Most craters form when something powerful strikes the Earth's surface, like a meteorite crashing down from space or a volcano exploding. When you see pictures of the moon's pockmarked surface, those circular dents are craters left by billions of years of space rocks smashing into it.

Earth has craters too, though many have worn away over time from weather and erosion. Meteor Crater in Arizona is nearly a mile wide and 550 feet deep, created 50,000 years ago when a meteorite slammed into the desert. Volcanoes also create craters when they erupt: the blast leaves a depression at the top called a volcanic crater, sometimes filling with water to form a crater lake.

You might also hear people use crater as a verb meaning to collapse inward or fail spectacularly. If someone says a project cratered, they mean it collapsed completely. A comedian's joke might crater if the audience sits in awkward silence. The word captures that sense of sudden, dramatic downward movement, like something falling and leaving a big dent behind.