Horizon

Etymology

Middle English horizon, from Late Latin horizont-, horizon, from Greek horizont-, horizōn, from present participle of horizein to bound, define, from horos boundary; perhaps akin to Latin urvum curved part of a plow

• Date: 14th century

Definitions

• 1 a : the apparent junction of earth and sky

b : the great circle on the celestial sphere formed by the intersection of the celestial sphere with a plane tangent to the earth's surface at an observer's position

c : range of perception or experience

d : something that might be attained <new horizons>

• 2 a : the geological deposit of a particular time usually identified by distinctive fossils

b : any of the reasonably distinct layers of soil or its underlying material in a vertical section of land

c : a cultural area or level of development indicated by separated groups of artifacts

Description

The horizon (Ancient Greek ὁ ὁρίζων, /ho horídzôn/, from ὁρίζειν, "to limit") is the apparent line that separates earth from sky. It is the line that divides all visible directions into two categories: those that intersect the Earth's surface, and those that do not. At many locations, the true horizon is obscured by trees, buildings, mountains, etc., and the resulting intersection of earth and sky is called the visible horizon. When looking at a sea from a shore, the part of the sea closest to the horizon is called the offing.