Definition of rumption in US English:

rumption

noun

English Regional, United States Regional, Scottish, Northern
informal
  • A rumpus, an uproar.

Origin

Early 19th century; earliest use found in The Sporting Magazine. Probably from rump- + -tion. Perhaps compare earlier polrumptious, and perhaps also slightly later ruction.

Pronunciation

rumption

/ˈrʌm(p)ʃən/