sidereal day

n.
The time required for a complete rotation of the earth in reference to any star or to the vernal equinox at the meridian, equal to 23 hours, 56 minutes, 4.09 seconds in units of mean solar time.

Note: click on a word meaning below to see its connections and related words.

The noun has one meaning:

Meaning #1: the time for one complete rotation of the earth relative to a particular star, about 4 minutes shorter than a mean solar day
  Synonym: day

---