follow Dictionary.com

Why is the ninth month called September?

sidereal day

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.
Origin
1785-1795
1785-95
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source
British Dictionary definitions for sidereal-day

sidereal day

noun
1.
See day (sense 5)
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
Cite This Source

Word of the Day

Difficulty index for sidereal day

Few English speakers likely know this word

Word Value for sidereal

9
10
Scrabble Words With Friends

Quotes with sidereal-day