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