形容詞 rumbustious:

1. noisy and lacking in restraint or discipline
   同義詞：boisterous, rambunctious, robustious, unruly

rum.bus.tious

adj.（形容詞）
Uncontrollably exuberant; unruly:
無控地喧鬧的；不守規(guī)矩的：
例句：
.Common to both his illustrations and his independent paintings . . . and lurking below their rumbustious surface, is a sympathy for the vulnerability of the ordinary human being.(Christopher Andreae)
.他的插圖和獨立圖畫的共同點是藏在歡鬧的表面下，有一種對于普通人的脆弱的同情心.(克里斯托弗·安德列亞)

來源：
Probably alteration of robustious
可能為 robustious的變化

【引伸】
rumbus.tiously
adv.（副詞）
rumbus.tiousness
n.（名詞）