mean sun

noun

: a fictitious sun used for timekeeping that moves uniformly along the celestial equator and maintains a constant rate of apparent motion equal to the average rate of apparent motion of the real sun

Word History

First Known Use

1765, in the meaning defined above

Time Traveler
The first known use of mean sun was in 1765

Dictionary Entries Near mean sun

Cite this Entry

“Mean sun.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/mean%20sun. Accessed 24 Feb. 2024.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!