Try Our Apps


Word of the Day
Tuesday, November 11, 2008

Definitions for sidereal

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

Learn something
new every day


Thank youfor signing up
Get the Word of the Day Email
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
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.