I. həˈrīz ə n noun
( -s )
Etymology: alteration (influenced by Late Latin horizon ) of Middle English orisonte, orizon, from Late Latin horizont-, horizon, from Greek horizont-, horizōn, from present participle of horizein to separate, part, bound, define, from horos boundary, limit + -izein -ize; akin to Latin urvus circumference of a city, Oscan uruvú boundary
1.
a. : a circle that bounds the part of the earth's surface visible from a given point : an apparent junction of earth and sky
b.
(1) : a great circle 90 degrees from the zenith and constituting the equator of the horizon system of coordinates
(2) : the circle in which a plane perpendicular to the direction of gravity intersects the celestial sphere
(3) : the plane tangent to the earth's surface at the observer's position
(4) : a level mirror (as the surface of mercury in a shallow vessel or a plane reflector adjusted to the true level artificially) used especially in observing altitudes — called also artificial horizon, false horizon
c. or horizon line : an imaginary line in a picture on which is projected the point of sight or station point of the spectator and which in a landscape replaces the natural horizon — compare perspective
d.
(1) : the fullest range or widest limit of perception, interest, appreciation, knowledge, or experience
the horizon of the human intellect has widened wonderfully during the past hundred years — C.W.Eliot
your horizon contracts, your mind's eye is focused upon a small circle of … details — Jan Struther
(2) : the range or limit of hope or expectation or a visible and seemingly attainable end or object lying within or upon it : goal , prospect
youth … demands of life some hope and horizon — John Buchan
China with its horizons of industrialization and trade — M.W.Straight
2.
a. : the geological deposit of a particular time, usually identified by distinctive fossils : a stratigraphic level or position in the geologic column : a natural soil layer ; also : zone
b. : any of the reasonably distinct layers of soil or its underlying material seen in a vertical section or profile of land and gradually developed as a result of natural soil-forming processes (as the incorporation of organic matter with disintegrated rock material) — see a-horizon , b-horizon , c-horizon , d-horizon
c.
(1) : a cultural area or level of development indicated by widely separated groups of artifacts showing cultural similarities (as in specific styles or objects)
(2) : a period of time indicated by a particular level of development in an excavated site
3. : horizon blue 2
Synonyms: see range
II. transitive verb
( -ed/-ing/-s )
: to limit by a horizon