sidereal Meaning, Definition & Usage

  1. adjective of or relating to the stars or constellations
    • sidereal bodies
    • the sidereal system
  2. adjective (of divisions of time) determined by daily motion of the stars
    • sidereal time

WordNet

Si*de"re*al adjective
Etymology
L. sidereus, from sidus, sideris, a constellation, a star. Cf. Sideral, Consider, Desire.
Definitions
  1. Relating to the stars; starry; astral; as, sidereal astronomy.
  2. (Astron.) Measuring by the apparent motion of the stars; designated, marked out, or accompanied, by a return to the same position in respect to the stars; as, the sidereal revolution of a planet; a sidereal day.

Webster 1913