observer

American  

[uhb-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,.  Also called aircraft observer.  U.S. Army. a person who serves in an aircraft as a reconnoiterer and directs artillery fire.

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observer British  

/ 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

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Other Word Forms

Derived Forms

• interobserver
  noun
• observership
  noun

Etymology

Origin of observer

First recorded in 1545–55; observe + -er ¹

Explanation

An observer is someone who watches or pays attention to something — if you're an observer of current events, you probably watch the news and read the newspaper every day to keep up with what's going on. You can be an accidental observer of something, like pedestrians who happen to witness an accident and become observers of it. Another kind of observer is one who notices things deliberately, like political observers who watch and comment on various events. Many newspapers once had the word observer in their names, from this second sense of the word. The verb observe has a Latin root, observare, which means "watch over, note, heed, or attend to."

Example Sentences

While this happened, researchers recorded activity throughout the observer fish's entire brain in real time.

From Science Daily • Jun. 2, 2026

Parsons is one such clear-eyed observer, able to take an internet phenomenon like liminal spaces and pick apart that fascination, studying what prompts the uncanny allure and transforming his findings into a complete, complex thesis.

From Salon • May 30, 2026

The disturbing thing is that it’s a question whose answer, to any well-read observer, is uncertain at best.

From Slate • May 27, 2026

The European Union's election observer mission nonetheless gave the election a clean bill of health.

From Barron's • May 8, 2026

"This morning, gentlemen, whilst I was sitting on the terrace, I was an observer of your activities. There could be little doubt of your purpose. You were searching the island for an unknown murderer?"

From "And Then There Were None" by Agatha Christie

Related Words

• bystander
• onlooker
• viewer
• watcher
• witness