Share this entry

sidereal day Line breaks: si|der¦eal day

Definition of sidereal day in English:


The time between two consecutive transits of the First Point of Aries. It represents the time taken by the earth to rotate on its axis relative to the stars, and is almost four minutes shorter than the solar day because of the earth’s orbital motion.
Example sentences
  • These sessions were performed during two consecutive days but delayed by 4 minutes per day, since the satellite sky distribution is repeated with a period close to a sidereal day.
  • Over the past few sidereal days more radio signals from an as-yet-unidentified source have been detected.
  • I understand the concepts of the sidereal day, and am happy with my intuitive notions of the Earth's rotation and movement relative to the sun and the solar system.

Definition of sidereal day in:

Share this entry


What do you find interesting about this word or phrase?

Comments that don't adhere to our Community Guidelines may be moderated or removed.

Get more from Oxford Dictionaries

Subscribe to remove adverts and access premium resources

Word of the day whippersnapper
Pronunciation: ˈwɪpəsnapə
a young, inexperienced person considered presumptuous or overconfident...