horizon Definition

horizon
noun

1. The line at which the Earth and the sky seem to meet. Also called sensible horizon, apparent horizon or visible horizon.
2. The plane through the Earth's centre parallel to the sensible horizon. Also called rational horizon.
3. astron.
The large circle in which the rational horizon meets the heavens.
4a. geol.
A level of strata characterized by some particular fossil or fossils;
4b. soil science.
A level of strata characterized by different physical properties of the soil;
4c. archaeol.
A level of strata characterized by artefacts from a particular culture or period.
5. The limit of a person's knowledge, interests or experience.

Thesaurus: purview, vista, range, scope, verge, ken, limit, perspective, prospect.

Etymology: 14c: from Greek horizon kyklos limiting circle, from horizein to limit.