observation

noun

ob·​ser·​va·​tion ˌäb-sər-ˈvā-shən 

-zər-

1

a

: an act or instance of observing a custom, rule, or law

observation of the dress code

b

: observance sense 3

The characters in her novel are based on close observation of her family.

2

a

: an act of recognizing and noting a fact or occurrence often involving measurement with instruments

weather observations

b

: a record or description so obtained

Scientific observations were sent to the committee.

3

: a judgment on or inference (see inference sense 2) from what one has observed

broadly : remark, statement

an insightful observation

based his observations on his own research

4

obsolete : attentive care : heed

5

: the condition of one that is observed

under observation at the hospital

observational

ˌäb-sər-ˈvā-sh(ə-)nəl 

-zər-

adjective

observationally adverb

Synonyms of observation

• attention
• awareness
• note
• mindfulness
• knowledge

Examples of observation in a Sentence

I'm not criticizing that kind of clothing. I'm just making an observation about the style.

Her constant observations about the weather bored me.

These facts are based on close observation of the birds in the wild.

Observations made using the telescope have led to new theories.

Some interesting observations came from the study.

He recorded his observations in a notebook.

Recent Examples on the Web

Near the end of the play, Majok’s script becomes, like Mann’s score, flatter and broader in its messaging, losing some of its sharpness of observation, and the humor that characterizes Kaysen’s memoir fades. —Jackson McHenry, Vulture, 5 June 2026

So Deng and his colleagues used those observations — along with satellite, pollution and weather data and models — then used artificial intelligence to create a nationwide data set of ozone levels that showed smog count at a resolution slightly higher than half a mile (1 kilometer). —ABC News, 4 June 2026

Gorski and his colleague, Northwestern physics and astronomy professor Elena Murchikova, used five years' worth of extremely deep observations from the Atacama Large Millimeter/Submillimeter Array (ALMA) radio telescopes in Chile. —Adam Harrington, CBS News, 4 June 2026

The discovery emerged from observations collected by Euclid, which is primarily tasked with investigating dark matter and dark energy. —Samantha Mathewson, Space.com, 4 June 2026

Word History

Etymology

Middle English observacioun "performance (of a religious rite), heeding (of rules, practices)," borrowed from Middle French & Latin; Middle French observacion "act of observing, performance of a prescribed rule," going back to Old French observation "law observed," borrowed from Latin observātiōn-, observātiō "action of watching, adherence (to rules, practices), usage, practice," from observāre "to give attention, watch carefully, abide by" + -tiōn-, -tiō, suffix of verbal action — more at observe

First Known Use

15th century, in the meaning defined at sense 1a

Phrases Containing observation

• for observation
• observation deck
• powers of observation
• self-observation
• under observation

Rhymes for observation

• abdication
• aberration
• abjuration
• abnegation
• abrogation
• acceptation
• acclamation
• acclimation
• accusation
• activation
• actuation
• acylation

Kids Definition

observation

noun

ob·​ser·​va·​tion

ˌäb-sər-ˈvā-shən, 

-zər-

1

: an act or an instance of observing a custom, rule, or law

2

: an act or the power of seeing or fixing the mind upon something

3

: an act of gathering information (as for scientific studies) by noting facts or occurrences

weather observations

4

: an opinion formed or expressed after observing

5

: the state of being observed

was in the hospital for observation

observational

-shnəl, 

-shən-ᵊl

adjective

Medical Definition

observation

noun

ob·​ser·​va·​tion ˌäb-sər-ˈvā-shən, -zər- 

1

: the noting of a fact or occurrence (as in nature) often involving the measurement of some magnitude with suitable instruments

temperature observations

also : a record so obtained

2

: close watch or examination (as to monitor or diagnose a condition)

postoperative observation

psychiatric observation