observer

noun

ob·​serv·​er əb-ˈzər-vər 

: one that observes: such as

a

: a representative sent to observe but not participate officially in an activity (such as a meeting or war)

b

: an expert analyst and commentator in a particular field

political observers

Synonyms of observer

• spectator
• viewer

Examples of observer in a Sentence

According to one observer, the event was poorly organized.

The star is not visible to an observer without a telescope.

According to one military observer, this change comes after years of planning.

Observers say the economy is improving.

The class has an observer today, so please be on your best behavior.

Recent Examples on the Web

This feeling can cause educators and other observers to lose sight of how the school itself can be part of the solution. — Jerome A. Graham, The Conversation, 19 Aug. 2026

Doubling down on sanctions Other observers have remained skeptical that the administration ever intended a swift military action in Cuba to bring about regime change. — Nora Gámez Torres, Miami Herald, 19 Aug. 2026

And yet the lesson of history is that alliance systems often prove more resilient in retrospect than contemporary observers expect at the time. — Kurt M. Campbell, Foreign Affairs, 18 Aug. 2026

On the other hand, relativity tells us that changing the observer’s frame of reference amounts to nothing but a transformation of spacetime coordinates so as to describe an object. — Aaron Shattuck, Scientific American, 18 Aug. 2026

Word History

Etymology

observe + -er entry 2

First Known Use

circa 1550, in the meaning defined above

Phrases Containing observer

• casual observer
• inter-observer

Rhymes for observer

• preserver
• fervor
• fervour
• server