sidereal

English

WOTD – 6 September 2006

From Latin sīdereus +‎ -al (cf. Latin sīderālis), from sīdus (“star, constellation”), of unknown ultimate origin, likely a substrate language such as Pre-Greek.

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sidereal

Wikipedia

sidereal (not comparable)

Of or relating to the stars.
- 1919, Hector Macpherson, “Chapter V”, in S.Chapman (series editor), editor, Men of Science: Herschel:
  The field of sidereal astronomy, therefore, was virtually untrodden when, shortly after the beginning of his telescopic work, Herschel began his first review of the heavens.
(astronomy) Relating to a measurement of time relative to the position of the stars.
- 1903, Percival Lowell, “Chapter I”, in The Solar System:
  Then, from a sufficient number of observations of synodic periods to give their mean, we obtain the sidereal period, or period with reference to the stars.
(astronomy) Relating to a measurement of time relative to the point of the vernal equinox.

of or relating to the stars

relating to a measurement of time relative to the position of the stars