horizon Meaning, Definition & Usage

noun the line at which the sky and Earth appear to meet
visible horizon; skyline; sensible horizon; apparent horizon.
noun the range of interest or activity that can be anticipated
purview; view.
- It is beyond the horizon of present knowledge
noun a specific layer or stratum of soil or subsoil in a vertical cross section of land
noun the great circle on the celestial sphere whose plane passes through the sensible horizon and the center of the Earth
celestial horizon.

F., fr. L. horizon, fr. Gr. (sc. ) the bounding line, horizon, fr. to bound, fr. boundary, limit.

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.
(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 ∨ celestial horizon. (c) (Naut.) The unbroken line separating sky and water, as seen by an eye at a given elevation, no land being visible.
(Geol.) 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.
(Painting) 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.