- someone or something that observes.
- a delegate to an assembly or gathering, who is sent to observe and report but not to take part officially in its activities.
- U.S. Air Force.
- a member of an aircrew, other than the pilot, holding an aeronautical rating.
- a person who maintains observation in an aircraft during flight.
- Also called air observer, aircraft observer. U.S. Army. a person who serves in an aircraft as a reconnoiterer and directs artillery fire.
- a person or thing that observes
- a person who attends a conference solely to note the proceedings
- a person trained to identify aircraft, esp, formerly, a member of an aircrew
n.1550s, “one who keeps a rule, custom, etc.,” agent noun from observe. Meaning “one who watches and takes notice” is from 1580s; this is the sense of the word in many newspaper names.