To tumble means to fall or roll in a clumsy, uncontrolled way. When a gymnast performs a controlled somersault, that's not tumbling. But when you trip over your shoelaces and go rolling down a hill, arms and legs going every which way, that's a tumble. A stack of books might tumble off a desk when someone bumps the table. Rocks tumble down a mountainside during a landslide.

The word captures that sense of chaotic, helpless motion. Unlike a careful fall where you catch yourself, a tumble happens when gravity takes over and you're just along for the ride. Kids tumble out of bed in the morning, puppies tumble over each other while playing, and acrobats practice tumbling routines that include rolls, flips, and cartwheels.

A tumbler is a type of drinking glass, named because early versions had rounded bottoms that would tumble over if you set them down, forcing you to finish your drink. In a clothes dryer, sometimes called a tumble dryer, your clothes tumble around as they dry. When prices or stocks tumble, they drop suddenly and dramatically, like something falling off a shelf.