astronomy (n.) Look up astronomy at Dictionary.com
c. 1200, from Old French astrenomie, from Latin astronomia, from Greek astronomia, literally "star regulating," from astron "star" (see astro-) + nomos "arranging, regulating; rule, law" from PIE root *nem- "to divide, distribute, allot" (see nemesis). Used earlier than astrology and originally including it.
Þer wes moni god clarc to lokien in þan leofte, to lokien i þan steorren nehʒe and feorren. þe craft is ihate Astronomie. [Layamon, "The Brut," c. 1200]