observer

plural observers

1. One who makes observations, monitors or takes notice.

   Most impartial observers agreed that Sampras had not served well.

   1 more example

   Between 8 and 9 p.m., the recorder at a meteorological station at Harrow, Middlesex, picked up 1,470 lightning flashes within a radius of 10 to 15 miles, and observers at the station described the storm as "probably one of the most spectacular of the century."

   1958 November 28, “Storm Damage in the Home Counties”, in Railway Magazine, page 746

   Synonyms: beholder, observator, onlooker · Antonyms: observee

2. One who adheres or follows laws, guidelines, etc.

   I shall be an observer of the local customs.

3. A person sent as a representative, to a meeting or other function to monitor but not to participate.

   The UN sent many observers to the country's first elections.

   1 more example

   When the army reached Tsun-i, an enlarged Politburo meeting was called. Teng attended as an observer.

   1985, Ching Hua Lee, “Becoming Mao's Man (1931-1935)”, in Deng Xiaoping: The Marxist Road to the Forbidden City, Princeton, N.J.: The Kingston Press, →ISBN, →LCCN, →OCLC, page 68

4. A country or other entity which has limited participation rights within an organization.

   The Vatican and Palestine have observer status at the UN.

5. governmentA crew member on an aircraft who makes observations of enemy positions or aircraft.

   The only crew-member to survive the crash was the Canadian observer.

6. governmentA sentry etc. manning an observation post.

   We waited till dusk when the observers' vision was poorest.

7. hobbiesSynonym of spotter.

   Synonyms: spotter