azimuth circle
nounDefinition of azimuth circle
1
: one of the great circles of the celestial sphere intersecting each other in the zenith and nadir
— called also vertical circle
— compare meridian sense 2
2
: a horizontal graduated circle for indicating azimuth (such as one having sight vanes and screens and attached to a compass to show magnetic azimuths or one having a telescope for accurate measurement of differences of azimuth)