旁观者指的是“即目睹事件的发生但并未参与的人”（a person who sees sth. that is happening but is not involved），该词有以下几种表达方法：

①Bystander（stander-by），“旁观则；局外人”，如：innocent bystanders at the scene of the accident 事故现场的无辜旁观者，It looks like an innocent bystander was killed instead of you. 看样子一位无辜的旁观者当了你的替死鬼。在此语境下，bystander的含义相当于“witness”（目击者）。中文里的“冷眼旁观”就可以表示为：the cool eye of a bystander。

②Onlooker（looker-on），“旁观者；观众”，如：A crowd of onlookers gathered at the scene of the crash. 在撞车地点聚集了一大群围观者。A handful of onlookers stand in the field watching. 少数旁观者站在场地里观看。通常Onlooker可与Bystander互换使用。

③Spectator，A spectator is someone who watches something, especially a sports event. (尤指体育赛事的) 观众，如Thirty thousand spectators watched the final game. 3万观众观看了那场决赛。

中文里的“当局者迷，旁观者清”就可分别用这三个词进行三种不同的表达：

①The spectators see the chess game better than the players.

②The onlooker sees most of the game.

③One who is in the game is blind, while a bystander sees through everything.

参考双语例句：

These include the fundamental nature of the right to life; the irreversible nature of death, and in some cases, disability; the potential of errors of fact and judgement; the possibility that innocent bystanders may be killed or wounded; the effect on the legitimacy of the police and the State; and the trauma suffered by everyone involved — which could include the police officers concerned — when a life is ended through violence.

这些原因包括生命权的根本性质；死亡以及在某些情况下致残的不可逆转性；发生事实和判断失误的可能性；无辜旁观者被杀或受伤的可能性；对警察和国家的合法性的影响；当暴力造成生命损失时，每个相关者受到的创伤——这可能包括有关的警察。

Reportedly present among the onlookers were the Acting Wali of Southern Darfur, the Commissioner of Kass and members of both the Government of the Sudan police and CRP.

据说旁观者中还有南达尔富尔州代理州 长、卡斯专员，以及中央后备警察和苏丹政府警察成员。

At this stage, the instruments studied include the Universal Declaration of Human Rights, the International Covenants on Human Rights, the Convention against Torture and Other Cruel Inhuman or Degrading Treatment or Punishment, the European Convention for the Prevention of Torture and Inhuman or Degrading Treatment or Punishment, the European Convention on the Control of the Acquisition and Possession of Firearms by Individuals, and the European Convention on Spectator Violence and Misbehaviour at Sports Events and in particular at Football Matches, all of which are in force in Portuguese domestic legislation.

在这一阶段，已研究的文书包括《世界人权宣言》、《国际人权公约》、《禁止酷刑和其他残忍、不人道或有辱人格的待遇或处罚公约》、《欧洲防止酷刑和不人道或有辱人格待遇或处罚公约》、《欧洲关于个人取得和持有火器管制公约》以及《欧洲关于体育赛事特别是足球比赛观众暴力和不端行为公约》，所有这些文书均在葡萄牙国内立法中有效。