- (n.) 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.
- (n.) A plane parallel to the sensible horizon of a place, and passing through the earth's center; -- called also rational / celestial horizon.
- (n.) The epoch or time during which a deposit was made.
- (n.) The unbroken line separating sky and water, as seen by an eye at a given elevation, no land being visible.
- (n.) 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.
- (n.) 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.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). horizon. Retrieved September 21, 2026, from http://smartdefine.org/horizon/definitions/2017332 |
| Chicago | Webster's. 2011. "horizon" http://smartdefine.org/horizon/definitions/2017332 (accessed September 21, 2026). |
| Harvard | Webster's 2011, horizon, Smart Define, viewed 21 September, 2026, <http://smartdefine.org/horizon/definitions/2017332>. |
| MLA | Webster's. "horizon" 27 May 2011. Web. 21 September 2026. <http://smartdefine.org/horizon/definitions/2017332> |