"Run riot" is an idiom that refers to when things are uncontrollable or when a situation becomes chaotic. There are several synonyms for this phrase, including "go crazy," "run amok," "lose control," "run wild," or "break loose." Each of these phrases is used to describe situations where people, animals, or things become uncontrollable and chaotic, causing confusion and destruction. Some other synonyms of "run riot" might include "rampage," "rebel," "unleash," "explode," or "berserk." These words emphasize the sense of chaos and disorder that comes when things are not kept under control. Whether applied to people, nature, or ideas, the phrase "run riot" suggests a departure from order and structure into chaos and confusion.