Celestial horizon and Great circle

Celestial horizon noun - The great circle on the celestial sphere whose plane passes through the sensible horizon and the center of the Earth.

Great circle and celestial horizon are semantically related. In some cases you can use "Great circle" instead a noun phrase "Celestial horizon".

Great circle noun - A circular line on the surface of a sphere formed by intersecting it with a plane passing through the center.

Celestial horizon and great circle are semantically related. Sometimes you can replace phrase "Celestial horizon" with "Great circle", this phrases are similar.