run rampant

phrase

: to be very common or to spread very quickly and in a way that is difficult to control

Rumors of her engagement ran rampant.

Examples of run rampant in a Sentence

Recent Examples on the Web

Opening with a performance by Sammie, the haunted house recreates Club Juke, where characters including Mary, Annie and Pearline run rampant. — Tanya Fedak, Variety, 4 Sep. 2026

Over in Marvel’s territory, the X-Men had their whole chronology readjusted when a time-traveling mutant killed off Professor Charles Xavier, allowing Apocalypse to run rampant. — Daniel Dockery, Vulture, 24 Aug. 2026

Cucumbers turn bitter, tomato flowers shrivel, leaves wilt, and pests such as whiteflies and spider mites run rampant across the fields. — Taylor Luck, Christian Science Monitor, 17 Aug. 2026

Eugenic ideas continue, like a dangerous genie released from its container and allowed to run rampant. — Kenny Fries, PEOPLE, 28 July 2026