aircraft-observer

noun

1. U.S. Army. observer(def 4).

noun

1. someone or something that observes.
2. a delegate to an assembly or gathering, who is sent to observe and report but not to take part officially in its activities.
3. U.S. Air Force.
   1. a member of an aircrew, other than the pilot, holding an aeronautical rating.
   2. a person who maintains observation in an aircraft during flight.
4. Also called air observer, aircraft observer. U.S. Army. a person who serves in an aircraft as a reconnoiterer and directs artillery fire.

noun

1. a person or thing that observes
2. a person who attends a conference solely to note the proceedings
3. 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.