Definition of vertical circle in US English:

vertical circle


  • A great circle of the celestial sphere whose diameter runs from zenith to nadir.

    • ‘These vertical circles are more obvious at the surface.’
    • ‘The three vertical circle detail is very uniting.’
    • ‘Alcabitius, which uses vertical circles, bears the name of the 12 th-century Arabian astrologer, Alchabitus.’