Chiefly Brit. rambunctious, boisterous, unruly, etc.
Origin of rumbustiousaltered (? after rum) ; from robustious
Uncontrollably exuberant; unruly: a rumbustious child, a rumbustious street market; a rumbustious political campaign.
Origin of rumbustiousAlteration of robustious.
Possibly alteration of robustious