Great circle and Vertical circle

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

Vertical circle and great circle are semantically related. In some cases you can replace phrase "Vertical circle" with "Great circle", this phrases are similar.

Vertical circle noun - A great circle on the celestial sphere passing through the zenith and perpendicular to the horizon.

Great circle and vertical circle are semantically related. You can use "Great circle" instead a noun phrase "Vertical circle".