ruckus (n.)

"disturbance, disorderly dispute," 1825, a dialectal or colloquial word of unknown origin. Perhaps from eruption or an altered shortening of insurrection.

"uproar, disturbance, riot," 1764 (Foote), a word of unknown origin, "prob. a fanciful formation" [OED], possibly an alteration of robustious "boisterous, noisy" (1540s; see robust). Rumpus room "play room for children in a family home" is from 1938.