Astronomical \As`tro*nom"ic*al\ (-[i^]*kal), a. [L. astronomicus, Gr. 'astronomiko`s: cf. F. astronomique.] Of or pertaining to astronomy; in accordance with the methods or principles of astronomy. -- {As`tro*nom"ic*al*ly}, adv. [1913 Webster] {Astronomical clock}. See under {Clock}. {Astronomical day}. See under {Day}. {Astronomical fractions}, {Astronomical numbers}. See under {Sexagesimal}. [1913 Webster]