horizon

[huh-rahy-zuh n] /həˈraɪ zən/

noun

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

Astronomy.

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)
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)

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

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

His horizons were narrow.

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

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

Origin

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

Synonyms

4. world, perspective, domain, viewpoint.

Examples from the web for horizon

When he saw fast-moving clouds on the horizon, he turned his group around.
Here's a look at what's on the horizon.
The closer the sun is to the horizon, the more of the circle we see.
Monstrous waves race together from every point of the horizon.
And along the state's highways, the vast sky stretches wide across the horizon.
Standing tall on stilt-like legs, a lone maned wolf scans the night horizon.
Small groves of tall mora trees stand out against the horizon.
Despite all the sunny projections, there are definite clouds on the horizon.
He pauses, gazing at the horizon.
Sitting on the sand and watching the horizon can be mesmerizing.

British Dictionary definitions for horizon

horizon

/həˈraɪzən/

noun

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

(astronomy)

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

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

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

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

on the horizon, likely or about to happen or appear

Derived Forms

horizonless, adjective

Word Origin

C14: from Latin, from Greek horizōn kuklos limiting circle, from horizein to limit, from horos limit

Word Origin and History for horizon

late 14c., orisoun, from Old French orizon (14c., Modern French horizon), earlier orizonte (13c.), from Latin horizontem (nominative horizon), from Greek horizon kyklos "bounding circle," from horizein "bound, limit, divide, separate," from horos "boundary." The h- was restored 17c. in imitation of Latin.

horizon in Science

horizon

(hə-rī'zən)

1. The apparent intersection of the Earth and sky as seen by an observer. Also called apparent horizon.
2. See celestial horizon.
3. See sensible horizon.
4. 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.
5. A specific layer of soil or subsoil in a vertical cross-section of land.
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.
Archaeology A period during which the influence of a particular culture spread rapidly over a defined area.

Idioms and Phrases with horizon

horizon

see: on the horizon