as ‧ tron ‧ o ‧ my /əˈstrɒnəmi $ əˈstrɑː-/ BrE AmE noun [uncountable]
[ Date: 1200-1300 ; Language: Old French ; Origin: astronomie , from Latin astronomia , from Greek , from astro- ( ⇨ ↑ astro- ) + -nomia 'arranging' ]
the scientific study of the stars and ↑ planet s ⇨ astrology