noisy and lacking in restraint or discipline
"a boisterous crowd"
"a social gathering that became rambunctious and out of hand"
"a robustious group of teenagers"
"beneath the rumbustious surface of his paintings is sympathy for the vulnerability of ordinary human beings"
"an unruly class"
incapable of being controlled
"the little boy's parents think he is spirited, but his teacher finds him unruly"
Wild; uncontrolled.