run riot or wild. Behave in a frenzied, out-of-control, or unrestrained manner. For example, I was afraid that if I left the toddler alone she would run amok and have a hard time calming down, or The weeds are running riot in the lawn, or The children were running wild in the playground. Amok comes from a Malay word for “frenzied” and was adopted into English, and at first spelled amuck, in the second half of the 1600s. Run riot dates from the early 1500s and derives from an earlier sense, that is, a hound's following an animal scent. Run wild alludes to an animal reverting to its natural, uncultivated state; its figurative use dates from the late 1700s.