IPA: /ˈbaɪˌstændər/
KK: /ˈbaɪˌstændər/
A person who is present at an event but does not take part in it.
The bystander witnessed the accident but did not intervene.
Bystander → It is formed from "by" (meaning near or beside) and "stand" (from Old English "standan", meaning to stand). The word "bystander" refers to someone who stands nearby, especially in a situation where something is happening.
Think of someone who is 'standing' ('stand') 'near' ('by') an event — that's why a bystander is someone who is nearby.