horizon

n 1: the line at which the sky and Earth appear to meet [syn: {apparent

horizon}, {visible horizon}, {sensible horizon}, {skyline}]

2: the range of interest or activity that can be anticipated;

"It is beyond the horizon of present knowledge" [syn: {view},

{purview}]

3: a specific layer or stratum of soil or subsoil in a vertical

cross section of land

4: the great circle on the celestial sphere whose plane passes

through the sensible horizon and the center of the Earth

[syn: {celestial horizon}]