vertical circle

noun

Astronomy.

1. a great circle on the celestial sphere passing through the zenith.

vertical circle

noun

1. astronomy a great circle on the celestial sphere passing through the zenith and perpendicular to the horizon

vertical circle

1. A great circle on the celestial sphere that passes through the zenith and the nadir and thus is perpendicular to the horizon.

Word History and Origins

Origin of vertical circle¹

First recorded in 1550–60