HORIZON
horizon, view, purview
(noun) the range of interest or activity that can be anticipated; “It is beyond the horizon of present knowledge”
horizon, apparent horizon, visible horizon, sensible horizon, skyline
(noun) the line at which the sky and Earth appear to meet
horizon, celestial horizon
(noun) the great circle on the celestial sphere whose plane passes through the sensible horizon and the center of the Earth
horizon
(noun) a specific layer or stratum of soil or subsoil in a vertical cross section of land
Source: WordNet® 3.1
Etymology
Noun
horizon (plural horizons)
The visible horizontal line or point (in all directions) that appears to connect the Earth to the sky.
Synonyms: skysill, skyline
(figuratively) The range or limit of one's knowledge, experience or interest; a boundary or threshold.
The range or limit of any dimension in which one exists.
(geology) A specific layer of soil or strata
(archaeology, mainly, US) A cultural sub-period or level within a more encompassing time period.
Any level line or surface.
(chess) The point at which a computer chess algorithm stops searching for further moves.
Source: Wiktionary
Ho*ri"zon, n. Etym: [F., fr. L. horizon, fr. Gr.
1. The circle which bounds that part of the earth's surface visible
to a spectator from a given point; the apparent junction of the earth
and sky.
And when the morning sun shall raise his car Above the border of this
horizon. Shak.
All the horizon round Invested with bright rays. Milton.
2. (Astron.)
(a) A plane passing through the eye of the spectator and at right
angles to the vertical at a given place; a plane tangent to the
earth's surface at that place; called distinctively the sensible
horizon.
(b) A plane parallel to the sensible horizon of a place, and passing
through the earth's center; -- called also rational or celestial
horizon.
(c) (Naut.) The unbroken line separating sky and water, as seen by an
eye at a given elevation, no land being visible.
3. (Geol.)
Definition: The epoch or time during which a deposit was made.
The strata all over the earth, which were formed at the same time,
are said to belong to the same geological horizon. Le Conte.
4. (Painting)
Definition: The chief horizontal line in a picture of any sort, which
determines in the picture the height of the eye of the spectator; in
an extended landscape, the representation of the natural horizon
corresponds with this line. Apparent horizon. See under Apparent.
– Artificial horizon, a level mirror, as the surface of mercury in
a shallow vessel, or a plane reflector adjusted to the true level
artificially; -- used chiefly with the sextant for observing the
double altitude of a celestial body.
– Celestial horizon. (Astron.) See def. 2, above.
– Dip of the horizon (Astron.), the vertical angle between the
sensible horizon and a line to the visible horizon, the latter always
being below the former.
– Rational horizon, and Sensible horizon. (Astron.) See def. 2,
above.
– Visible horizon. See definitions 1 and 2, above.
Source: Webster’s Unabridged Dictionary 1913 Edition