rumpus (n.)youdaoicibaDictYouDict[rumpus 词源字典]
1764, of unknown origin, "prob. a fanciful formation" [OED], possibly an alteration of robustious "boisterous, noisy" (1540s; see robust). First record of rumpus room "play room for children in a family home" is from 1938.[rumpus etymology, rumpus origin, 英语词源]