bystanderWiktionary 原文中文来自 ECDICTn.旁观者，目击者构词拆分by-前缀(now mostly non-productive) Town or city.+stander词根/词干词源说明From by- + stander. Compare passerby.释义（英文）名词 NounA person who, although present at some event, does not take part in it; an observer, witness, or spectator.词族派生词（4）bystanderishbystandershipbystander effectinnocent bystander