looker-on
noun [ C ] uk/ˌlʊk.ərˈɒn/ us/ˌlʊk.ɚˈɑːn/ lookers-on
旁观者
someone who watches something that is happening in a public place but is not involved in it
At every gathering for dances, sports, or games of any kind there are more lookers-on than participants. 每次舞蹈、体育或其他比赛的活动中，旁观者都比参与者多。
Synonym: onlooker