horizon

[huh-rahy-zuhn]
noun
1.
the line or circle that forms the apparent boundary between earth and sky.
2.
Astronomy.
a.
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)
b.
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.
5.
Geology. a thin, distinctive stratum useful for stratigraphic correlation.
6.
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


4. world, perspective, domain, viewpoint.
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source Link To horizons
Collins
World English Dictionary
horizon (həˈraɪzən)
 
n
1.  visible horizon, Also called: apparent horizon the apparent line that divides the earth and the sky
2.  astronomy
 a.  Also called: sensible horizon the circular intersection with the celestial sphere of the plane tangential to the earth at the position of the observer
 b.  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 horizon B horizon See C horizon a layer in a soil profile having particular characteristics
6.  on the horizon likely or about to happen or appear
 
[C14: from Latin, from Greek horizōn kuklos limiting circle, from horizein to limit, from horos limit]
 
ho'rizonless
 
adj

Collins English Dictionary - Complete & Unabridged 10th Edition
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009
Cite This Source
Etymonline
Word Origin & History

horizon
late 14c., from O.Fr. orizon (14c.), earlier orizonte (13c.), from L. horizontem (nom. horizon), from Gk. horizon kyklos "bounding circle," from horizein "bound, limit, divide, separate," from horos "boundary." The h- was restored 17c. in imitation of Latin. Horizontal (1550s) originally meant "relating
to or near the horizon," later (1638) parallel to it, "flat."
Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
American Heritage
Science Dictionary
horizon   (hə-rī'zən)  Pronunciation Key 
    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.

  1. 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.

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


The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
Example sentences
Shining backwards, singing downwards towards horizons blue and bay.
Complexity had extended itself on immense horizons, and arithmetical ratios
  were useless for any attempt at accuracy.
History and science spread out in personal horizons towards goals no longer far
  away.
There can no more be three unities in the drama than three horizons in a
  picture.
Copyright © 2014 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature
FAVORITES
RECENT

;