An avalanche is a massive amount of snow that suddenly breaks loose and rushes down a mountainside, gathering speed and power as it falls. Imagine thousands of tons of snow, ice, and rocks tumbling downward faster than a car on a highway, with enough force to snap trees, crush buildings, and bury everything in its path.

Avalanches happen when snow builds up on steep slopes until something triggers the collapse: a loud noise, changing weather, or even just one extra bit of weight. The snow can start as a small crack but quickly becomes a roaring wall of white that grows larger as it picks up more snow. Mountain climbers, skiers, and people living in snowy mountain areas take avalanches very seriously because they're extremely dangerous and difficult to escape once they start.

People also use avalanche to describe any overwhelming rush of things. A teacher might receive an avalanche of emails from worried parents, or a bakery might face an avalanche of orders before a holiday. In these cases, the word captures that same feeling of being suddenly buried under far more than you can handle.