difficult to control or handle; wildly boisterous: a rambunctious child.
turbulently active and noisy: a social gathering that became rambunctious and out of hand.
Origin of rambunctious
An Americanism dating back to 1820–30; origin uncertain
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
informal boisterous; unruly
Word Origin for rambunctious
C19: probably from Icelandic ram- (intensifying prefix) + -bunctious, from bumptious
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
1859, earlier rumbunctious, 1830, probably altered (by influence of ram) from rumbustious.
Online Etymology Dictionary, © 2010 Douglas Harper