# horizon

Pronunciation: say "huh-RY-zuhn" /həˈɹaɪ.zən/

## Noun

1. The visible line in the distance where the sky appears to meet the earth or sea.
   - Simple: The faraway line where the sky seems to meet the ground or the sea.
   - _A thin band of orange light spread along the horizon at dawn._
   - _From the summit, the curve of the horizon stretched in every direction._
2. The outer bounds of a person's knowledge, experience, or interests, or more generally any boundary or threshold.
   - Simple: The limit of what someone knows, has done, or cares about.
   - _Studying philosophy pushed the horizon of his thinking far beyond what he expected._
   - _Travel has a way of broadening one's horizons._
3. The boundary or extent of any dimension within which a person exists.
   - Simple: The outer limit of any span you live within, such as time or space.
   - _Mortality forms the ultimate horizon of every human life._
   - _Within the horizons of a single lifetime, only so much can ever be accomplished._
4. A level line or surface of any kind.
   - Simple: A flat, level line or surface of any kind.
   - _Far from any coastline, the navigator poured mercury into a shallow tray to give his sextant a true horizon._
   - _He aligned the new shelf to the horizon marked by his spirit level._
5. A distinct layer of soil or rock within a vertical sequence.
   - Simple: A layer of soil or rock that lies under or over other layers.
   - _Geologists labeled each horizon by its color and texture._
   - _The upper horizon held far more organic matter than the layers beneath it._
6. A cultural sub-period or level situated within a larger span of time. *(US)*
   - Simple: A short cultural period found within a longer span of history.
   - _The excavation revealed artifacts from a distinct cultural horizon._
   - _Researchers dated the horizon to roughly the twelfth century._
7. The point at which a chess-playing program stops searching for further moves.
   - Simple: In computer chess, the point where the program stops looking ahead at moves.
   - _The chess engine evaluated every line up to its horizon, then stopped._
   - _Extending the horizon by two plies sharpened the program's tactical vision._

## Origin

This word came into Middle English through Middle and Old French, ultimately from Latin 'horizōn' and Ancient Greek 'horízōn', which derives from 'hóros' meaning 'boundary'.

Source: DictionaryAI, https://dictionaryai.com/define/horizon (written from Wiktionary data, CC BY-SA 4.0: https://creativecommons.org/licenses/by-sa/4.0/).