adj. (also astronomic)
1. of or relating to astronomy.
2 extremely large; too large to contemplate.
Phrases and idioms:
astronomical unit a unit of measurement in astronomy equal to the mean distance from the centre of the earth to the centre of the sun, 1.495 x 10(11) metres or 92.9 million miles. astronomical year see YEAR n. 1.
Derivatives:
astronomically adv.
Etymology: L astronomicus f. Gk astronomikos