horizon

American  

[huh-rahy-zuhn] / həˈraɪ zən /

noun

• horizons
  plural

1. 

   the line or circle that forms the apparent boundary between earth and sky.

2. Astronomy.

   1. the small circle of the celestial sphere whose plane is tangent to the earth at the position of a given observer, or the plane of such a circle sensible horizon.

   2. Also called rational horizon.  the great circle of the celestial sphere whose plane passes through the center of the earth and is parallel to the sensible horizon of a given position, or the plane of such a circle celestial horizon.

3. the limit or range of perception, knowledge, or the like.

4. Usually horizons the scope of a person's interest, education, understanding, etc..

   His horizons were narrow.

   Synonyms:

   viewpoint, domain, perspective, world

5. Geology. a thin, distinctive stratum useful for stratigraphic correlation.

6. Also called soil horizon.  any of the series of distinctive layers found in a vertical cross section of any well-developed soil.

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horizon British  

/ həˈraɪzən /

noun

1. Also called: visible horizon.   apparent horizon.  the apparent line that divides the earth and the sky

2. astronomy

   1. Also called: sensible horizon.  the circular intersection with the celestial sphere of the plane tangential to the earth at the position of the observer

   2. Also called: celestial horizon.  the great circle on the celestial sphere, the plane of which passes through the centre of the earth and is parallel to the sensible horizon

3. the range or limit of scope, interest, knowledge, etc

4. a thin layer of rock within a stratum that has a distinct composition, esp of fossils, by which the stratum may be dated

5. a layer in a soil profile having particular characteristics See A horizon B horizon C horizon

6. likely or about to happen or appear

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horizon Scientific  

/ hə-rī′zən /

1. 1. The apparent intersection of the Earth and sky as seen by an observer.

   2. See celestial horizon

   3. See sensible horizon

2. Geology

   1. A specific position in a stratigraphic column, such as the location of one or more fossils, that serves to identify the stratum with a particular period.

   2. A specific layer of soil or subsoil in a vertical cross-section of land.

3. Archaeology A period during which the influence of a particular culture spread rapidly over a defined area.

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horizon Idioms  

1. see on the horizon.

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Other Word Forms

Derived Forms

• horizonless
  adjective

Inflected Forms

Nouns

• horizons
  plural

Etymology

Origin of horizon

First recorded in 1540–50; from Latin horizōn, from Greek horízōn (kýklos) “bounding (circle),” equivalent to horíz(ein) “to bound, limit” + -ōn present participle suffix (nominative singular); replacing Middle English orizonte, from Middle French, from Latin horizontem, accusative of horizōn

Explanation

When you look out your window and note the furthest point you can see––the line where the sky meets the earth––that edge is called the horizon. Horizon can also mean the edge of something in a figurative sense. When you are thinking about your life, it can be difficult to get very far beyond where you are. Teenagers have a hard time imagining beyond the horizons of young adulthood. People expecting a baby often put much of their focus on infancy––having a child who can sit up or even walk is beyond the horizons of their thinking.

Example Sentences

See Examples For:

horizon horizons

Energy futures settled lower on Friday on the heels of a report calling for more demand destruction on the horizon.

From MarketWatch ● Sep. 11, 2026

Canada's retaliatory tariffs on a range of US goods came into effect on Tuesday, with no sign of a trade deal on the horizon.

From BBC ● Sep. 8, 2026

California beat several bluebloods in the transfer portal and continues to win high school recruiting battles, with an elite 2027 class on the horizon led by Westlake wideout Charles Davis and Chaparral quarterback Dane Weber.

From Los Angeles Times ● Sep. 4, 2026

From restructuring to the loan's role in Senegal's ongoing political drama, here is what is likely on the horizon.

From Barron's ● Sep. 3, 2026

For the first time in his life, they weren’t just a distant darkness on the eastern horizon.

From "Wolf Brother" by Michelle Paver

It opened up my horizons to a lot of different forms of working out that I just didn’t know before.

From Los Angeles Times ● Sep. 14, 2026

Regardless, should you ever feel that many people around you are looking increasingly smooth, there’s an easy solution that does not require Twilight Zone–style exile from society: Expand your social horizons a bit.

From Slate ● Sep. 2, 2026

The VC business is built on longer time horizons, higher levels of risk and the potential for outsize payoffs tied to meaningful breakthroughs in technology.

From The Wall Street Journal ● Aug. 3, 2026

For moon watchers in Gloucestershire, Cleeve Hill, Painswick Beacon and May Hill are high ground locations offering wide horizons and clear vantage points.

From BBC ● Jul. 28, 2026

He had broken through the horizons into a cold and lonely outside.

From "The Pearl" by John Steinbeck

Related Words

• boundary
• perspective
• prospect
• scope