n. pl. as·tron·o·mies
1. The scientific study of matter and phenomena in the universe, especially in outer space, including the positions, dimensions, distribution, motion, composition, energy, and evolution of celestial objects.
2. A system of knowledge or beliefs about celestial phenomena: the various astronomies of ancient civilizations.
[Middle English astronomie, from Old French, from Latin astronomia, from Greek astronomiā : astro-, astro- + -nomiā, -nomy.]
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