kangaroo court

【英文解釋】irregular court, especially one held by striking workers to punish breaches of their rules.

【中文解釋】[貶]“袋鼠法庭”（私設的公堂或非正規(guī)的法庭，多用于懲罰同伙者）

【短語來源】Kangaroo courts originated in American prisons in the 19th century as secret, though sometimes condoned, gathering of inmates to regulate the sharing of tobacoo or money or to deal with breaches of the prisoners' code of behaviour. The explanation that kangaroo was used in allusion to Australia's history as a prison colony is rather far-fetched. The more likely origin is a comparison between the kangaroo's unconventional method of movement and prisoners who 'jumped over' the rules.

袋鼠法庭于19世紀在美國監(jiān)獄秘密發(fā)展起來，一些監(jiān)獄罪犯制定共同的規(guī)則管理煙或者錢（監(jiān)獄里面花點兒錢抽個煙不容易啊，相信大家在電視上看到過不少這些畫面），并懲罰那些違反規(guī)則的犯人。有解釋說kangaroo是暗示澳洲作為殖民地監(jiān)獄的歷史，這種解釋相當牽強。（偶來插一句~~在歷史上，澳洲曾是英國滴殖民地，并且在18世紀后期，英國人首先把澳大利亞作為一個流放囚犯的地方，所以有殖民地監(jiān)獄這么一說。）
更有說服力的說法是關于袋鼠特別的行動方式（也就是走路一跳一跳啦~~）和監(jiān)獄犯人“跳出”規(guī)則的對比。

【有例有句】It's illegal to set kangaroo court.

私設法庭是違法的。