DICT.TW Dictionary Taiwan

 si·de·re·al /saɪˈdɪriəl, sə-/
 (a.)星的,恆星的,以星球的運行為基準的

 Si·de·re·al a.
 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.
 Sidereal clock, day, month, year. See under Clock, Day, etc.
 Sideral time, time as reckoned by sideral days, or, taking the sidereal day as the unit, the time elapsed since a transit of the vernal equinox, reckoned in parts of a sidereal day. This is, strictly, apparent sidereal time, mean sidereal time being reckoned from the transit, not of the true, but of the mean, equinoctial point.
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 sidereal
      adj 1: of or relating to the stars or constellations; "sidereal
             bodies"; "the sidereal system"
      2: (of divisions of time) determined by daily motion of the
         stars; "sidereal time" [ant: civil]