Hour angle

( Astron.) The angle at the pole, between the celestial meridian and the circle of declination pa ing through the place of the body. Hour-circle, n . ( Astron . ) The meridian of any place, or any great circle of the globe pa ing through the poles, is so called, because the hour of the day at any place can be ascertained, when the great circle on which the sun happens to be at that time is known.