English to English

adjective (a)

• of or relating to the stars or constellations(adj.pert)

  Example:
  Sidereal bodies.
  The sidereal system.
  

  source: wordnet30
• (of divisions of time) determined by daily motion of the stars(adj.all)

  Example:
  Sidereal time.
  

  Antonym:
  civil
  

  source: wordnet30
• Relating to the stars; starry; astral; as, sidereal astronomy.(adjective)

  source: webster1913