Definition of sideral in English:

sideral

adjective

rare
  • Of or relating to the stars; starry; = "sidereal".

Origin

Mid 16th century; earliest use found in George Joye (1490x95–1553), evangelical author. From classical Latin sīderālis of or concerned with the stars or constellations from sīder-, sīdus celestial object, star, planet, constellation, comet (of unknown origin) + -ālis.

Pronunciation

sideral

/ˈsʌɪdərəl/