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.
a clock used for observing the apparent time of the meridian passages of heavenly bodies.
Origin of astronomical clock
First recorded in 1855–60
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
a complex clock showing astronomical phenomena, such as the phases of the moon
any clock showing sidereal time used in observatories
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012