Dictionary.com
definitions
  • synonyms

sidereal day

See more synonyms for sidereal day on Thesaurus.com
noun Astronomy.
  1. the interval between two successive passages of the vernal equinox over the meridian, being about four minutes shorter than a mean solar day.
Show More

Origin of sidereal day

First recorded in 1785–95
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for sidereal day

sidereal day

noun
  1. See day (def. 5)
Show More
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012