看热闹的人;旁观者
Bystander \By"stand`er\, n. [By + stander, equiv. to stander-by; cf. AS. big-standan to stand by or near.] One who stands near; a spectator; one who has no concern with the business transacting. He addressed the bystanders and scattered pamphlets among them. --Palfrey. Syn: Looker on; spectator; beholder; observer.
bystander n : a nonparticipant spectator