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bystander

American  
[bahy-stan-der] / ˈbaɪˌstæn dər /

noun

  1. a person present but not involved; chance spectator; onlooker.

    Synonyms:
    sidewalk superintendent , rubberneck , witness , passerby , viewer , observer

bystander British  
/ ˈbaɪˌstændə /

noun

  1. a person present but not involved; onlooker; spectator

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of bystander

First recorded in 1610–20; by- + stand ( def. ) + -er 1 ( def. )

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Even after Blanc arrives, he’s confounded to find himself occasionally standing on the sidelines, a bystander in Jud’s moral crusade to herd his congregation toward righteousness.

From Los Angeles Times

Scientists have long debated whether water in these confined regions simply behaves as a passive bystander or affects how molecules interact.

From Science Daily

Brendan Moylan, a member of parliament for Northern Tablelands, the region where Walcha is located, thanked emergency responders and other bystanders for their "swift and incredibly professional work at the scene".

From BBC

It made me realise that bystanders can feel incredibly conflicted about taking action.

From BBC

Police and bystanders rescued the group, but one woman suffered a heart attack and could not be revived.

From Barron's