observer

[uh b-zur-ver] /əbˈzɜr vər/
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.
Origin
1545-55; observe + -er1
Related forms
observership, noun
interobserver, noun
Examples from the web for observer
  • There are so many different layers of animal care that might not be obvious to the casual observer.
  • To be up there in the cold and the dark, riding in the observer's cage and carefully.
  • Surveying the serried ranks of people, one observer said they were jammed so closely.
  • And so, rock climbing is not really mind over matter, even if it looks that way to the admiring observer.
  • These compact systems allow scientists to study animal behavior without interference by a human observer.
  • If you're aware of it-if you're an observer-you do notice these things along the way.
  • As a result, a clock speeding away from an observer will appear to tick slower than a stationary clock.
  • But many of my visual observer friends tell me it didn't look much different from any other full moon.
  • Their faint marks reveal themselves only to the careful observer.
  • Gravitation naturally does not exist for this observer.
British Dictionary definitions for observer

observer

/əbˈzɜːvə/
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
Word Origin and History for observer
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.