astronomical clock

astronomical clock Word Origin noun

1. a clock indicating or representing the movements of the sun or planets, the phases of the moon, or the sky visible at a given time, used as a means of establishing time or for additional information, as locating celestial bodies or timing their movement.
2. a clock used for observing the apparent time of the meridian passages of heavenly bodies.

Origin of astronomical clock First recorded in 1855–60 British Dictionary definitions for astronomical clock astronomical clock noun

1. a complex clock showing astronomical phenomena, such as the phases of the moon
2. any clock showing sidereal time used in observatories