Rambunctious means "noisy and out of control," like a rambunctious child who is so hard to handle that no babysitter has ever come back a second time. People who are rambunctious, pronounced "ram-BUNK-shus," can be fun — to a point.
adjective. difficult to control or handle; wildly boisterous: a rambunctious child. turbulently active and noisy: a social gathering that became rambunctious and out of hand.
In changing its connotation over time, “rambunctious” is hardly alone. But its general direction — from negative to positive — is a bit unusual.
Cautious dictionaries say “of unknown origin”, an open invitation to strange and inventive suggestions. ... The Oxford English Dictionary argues that it's a variant of the earlier rumbustious, recorded from about 1777, that meant boisterous, turbulent or unruly.