ephem·​er·​is i-ˈfe-mə-rəs How to pronounce ephemeris (audio)
plural ephemerides ˌe-fə-ˈmer-ə-ˌdēz How to pronounce ephemeris (audio)
: a tabular statement of the assigned places of a celestial body for regular intervals

Examples of ephemeris in a Sentence

Recent Examples on the Web According to astrologer Annie Heese's ephemeris (aka her table of future planetary activity), summer 2018 will see seven planetary retrogrades in total, although the most planets that will be retrograde at one time is six. refinery29.com, 26 June 2018 Read on to learn how each sign affects the new moon's pensive energy, and to find out when new moon will arrive in your sign next (dates are in EST, according to NASA and astrologer Annie Heese's ephemerides). refinery29.com, 11 May 2018 To follow Uranus, check out a planetary ephemeris or this nifty daily breakdown. Aliza Kelly Faragher, Allure, 10 May 2018

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'ephemeris.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


Latin, diary, ephemeris, from Greek ephēmeris, from ephēmeros

First Known Use

1508, in the meaning defined above

Time Traveler
The first known use of ephemeris was in 1508

Dictionary Entries Near ephemeris

Cite this Entry

“Ephemeris.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ephemeris. Accessed 21 Sep. 2023.

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