Astronomy

As·tron·o·my

Astronomy

n.
  1. Astrology. [Obs.]
    Not from the stars do I my judgment pluck; And yet methinks I have astronomy.
  2. The science which treats of the celestial bodies, of their magnitudes, motions, distances, periods of revolution, eclipses, constitution, physical condition, and of the causes of their various phenomena.
  3. A treatise on, or text-book of, the science.

Phrases & Compounds
Physical astronomy
See under Physical.