run riot

Verb

run riot (third-person singular simple present runs riot, present participle running riot, simple past ran riot, past participle run riot)

1. (idiomatic) To act in an uncontrolled, unbridled manner.
   • In their idea, there is scarcely a finer tree than the Kavika; and when in their fairy tales the imagination runs riot, and describes all that is lovely and beautiful, the Kavika is rarely omitted.1862, Berthold Seemann, Viti: an account of a government mission to the Vitian or Fijian Islands, in the years 1860-61, Cambridge: Macmillan & Co., →OCLC, page 318
   • No wonder, then, that against a background of surging aggressive prosperity, South Wales built up during the last half of the nineteenth century a local railway system of great density and complexity, in which almost every company competed with every other in its area, and in which working...1939 September, D. S. Barrie, “The Railways of South Wales”, in Railway Magazine, page 158
2. (idiomatic) To be uncontrollable.
   • And it was only the defiance of Cech that kept a rampant Spurs at bay in the second half, producing a collection of outstanding saves to somehow keep Arsenal in contention as Pochettino's side threatened to run riot.2018 February 10, Phil McNulty, “Tottenham Hotspur 1 - 0 Arsenal”, in BBC