observer
/əbˈzɜrvər/
noun
- A person who watches or notices something, especially in order to learn or understand.
- A careful observer can tell when someone is lying by their body language.
- As an observer at the meeting, she took notes but did not speak.
- The bird observer sat quietly with binoculars, waiting for the eagle to appear.
- A person who attends an event or situation to monitor or report on it, often officially.
- The military observer reported on the ceasefire from the front lines.
- The United Nations sent an observer to monitor the election.
- A weather observer records temperature and rainfall every day.
Antonyms