sidereal

adjective

si·​de·​re·​al sī-ˈdir-ē-əl How to pronounce sidereal (audio)
sə-
: of, relating to, or expressed in relation to stars or constellations : astral

Examples of sidereal in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Called sidereal time, the measurement calculates the length of a day by comparing the earth's rotation to the stars. Aaron Pressman, Fortune, 12 Apr. 2017 One tweet, in particular, has birthed a fair number of inky astronauts floating across a sidereal arm. Jesse Lichtenstein, New York Times, 15 June 2017 With this definition, a sidereal year is something like 365.256363 solar days. Rhett Allain, WIRED, 29 Feb. 2012

Word History

Etymology

Latin sidereus, from sider-, sidus star, constellation

First Known Use

1612, in the meaning defined above

Time Traveler
The first known use of sidereal was in 1612

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Dictionary Entries Near sidereal

Cite this Entry

“Sidereal.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/sidereal. Accessed 1 Dec. 2024.

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