/əbˈzɜːvər/ – Noun
Definition: người quan sát, người dự thính, quan sát viên.
A more thorough explanation: An observer is a person who attends an event, such as a meeting or trial, to watch and take note of what transpires without actively participating or having a direct stake in the proceedings.
Example: The observer testified in court that they saw the defendant enter the building at the time of the crime.