Word origin · etymology
Latin-derived modifier and Greek-derived noun.
Horizon comes from Greek horizōn, bounding or defining. Local specifies the observer's own dividing plane between visible and hidden sky.
How we know · epistemology
Observer-based coordinate reference
The reference depends on the observer’s position. A calculated zero-altitude direction belongs to this idealized frame; it does not describe every obstruction in the visible skyline.
Skyfield: Positions — local altitude, azimuth and atmospheric refraction ↗
Connected concepts
Mentioned in 3 other entries
These links connect subjects and terminology. They do not establish a shared historical origin.
Sources & provenance
Use the citations beside each section to distinguish a calculation convention, a historical teaching and an editorial example.