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Word of the Day
Monday, July 20, 2015

Definitions for sidereal

  1. Astronomy. determined by or from the stars: sidereal time.
  2. Astronomy. of or pertaining to the stars.

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Citations for sidereal
The sparkling points of light flashed past me in an interminable stream, as though the whole sidereal system were dropping into the void. Jack London, The Sea Wolf, 1904
What were they doing out there? Who governed them? When were their sidereal motions calculated? Theodore Dreiser, The "Genius," 1915
Origin of sidereal
1625-1635
Though the term looks like a combination of side and real, it comes from the Latin word sīdus, meaning "star, constellation," with the suffix -al, meaning "pertaining to," as in the common word natural.