observer

US /əbˈzɝː.vɚ/
UK /əbˈzɝː.vɚ/
"observer" picture
1.

a person who watches or notices something

:
•
She was a keen observer of human nature.
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The police had an observer at the protest.
:
spectatoronlookerviewerwitnessmonitor
2.

a person who attends a meeting or event without participating in it

:
•
She attended the conference as an observer, not a speaker.
•
International observers were present during the elections.
:
monitorauditorinspector
:
observationobserveobservation car