1
pundit
1
radar
1
reconnoiterer
1
ref
1
reviewer
1
rubberneck(noun, spectator)
1
scout(noun, plant, watch, guard, agent)
1
scrutineer
1
secret agent(noun, expression, plant, agent, operative)
1
secret service(noun, expression, plant, agent, operative)
1
seer
1
sidewalk superintendent
1
sightseer(noun, spectator)
1
sleeper(noun, plant, agent, operative, informer)
1
sleuth(noun, plant, agent, spy, operative)
1
snoop(noun, plant, agent, spy, operative)
1
spectatress
1
spectatrix
1
spier
1
spook(noun, plant, agent, operative, informer)
10 years ago|8.4k views|share |citing 
APASmart Define. (2016). observer thesaurus. Retrieved September 20, 2026, from https://smartdefine.org/observer/thesaurus/synonyms
ChicagoSmart Define. 2016. "observer thesaurus" https://smartdefine.org/observer/thesaurus/synonyms (accessed September 20, 2026).
HarvardSmart Define 2016, observer thesaurus, Smart Define, viewed 20 September, 2026, <https://smartdefine.org/observer/thesaurus/synonyms>.
MLASmart Define. "observer thesaurus" 26 February 2016. Web. 20 September 2026. <https://smartdefine.org/observer/thesaurus/synonyms>