Amok means wildly out of control, in a state of violent or frenzied behavior. When something runs amok, it's going crazy in a dangerous or destructive way. If a bull broke loose from its pen and charged through a farmer's market, knocking over fruit stands and scattering people in every direction, you could say it was running amok.

Today, we use it more broadly and often playfully. You might say that your little brother's imagination ran amok when he turned the living room into an elaborate blanket fort that swallowed three chairs and the coffee table. Or a science experiment could go amok when the volcano you built erupts with way more fizz than expected, spilling “lava” across the kitchen counter.

When people say something is running amok, they mean it's completely escaped control and is causing chaos. The phrase suggests motion and energy: things don't just sit there being chaotic, they're actively spreading disorder wherever they go. A rumor can run amok through a school, growing wilder with each retelling. Weeds can run amok in a neglected garden, taking over every flower bed.