Noun horizon has 4 senses
  1. horizon, apparent horizon, visible horizon, sensible horizon, skyline - the line at which the sky and Earth appear to meet
    --1 is a kind of line
    --1 is a part of perspective, linear perspective
  2. horizon, view, purview - the range of interest or activity that can be anticipated; "It is beyond the horizon of present knowledge"
    --2 is a kind of scope, range, reach, orbit, compass, ambit
  3. horizon - a specific layer or stratum of soil or subsoil in a vertical cross section of land
    --3 is a kind of
    --3 is a part of profile
    --3 has particulars: soil horizon; geological horizon
  4. horizon, celestial horizon - the great circle on the celestial sphere whose plane passes through the sensible horizon and the center of the Earth
    --4 is a kind of great circle