ephemeris

[ ih-fem-er-is ]

See synonyms for ephemeris on Thesaurus.com

noun,plural e·phe·mer·i·des

[ef-uh-mer-i-deez]. /ˌɛf əˈmɛr ɪˌdiz/.

a table showing the positions of a heavenly body on a number of dates in a regular sequence.
an astronomical almanac containing such tables.

Archaic. an almanac or calendar.

Origin of ephemeris

1545–55; <Latin ephēmeris day book, diary <Greek ephēmerís diary, account book, derivative of ephḗmeros;see ephemeral

Words Nearby ephemeris

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use ephemeris in a sentence

In the 1790s, he calculated ephemerides, predictions about the future positions of the sun, the moon, the planets and the stars over the course of the coming year.
U.S. worries about space aliens and UFOs are older than you think | Gordon Fraser | June 25, 2021 | Washington Post
Not surprisingly, with such traumatic lessons, scientists have sweated over getting the ephemerides of solar-system objects pinned down better and better.
We Never Know Exactly Where We’re Going in Outer Space - Issue 92: Frontiers | Caleb Scharf | November 4, 2020 | Nautilus
Dictys (the full title of whose book is ephemeris Belli Trojani) is not only the longer but the better written of the two.
The Flourishing of Romance and the Rise of Allegory | George Saintsbury
For instance, under the entry newspaper occurs the attractive word ephemeris.
Public Speaking | Clarence Stratton
Knowing the location of Venus in the sky, which can be ascertained from the ephemeris, the observer can find it by day.
Pleasures of the telescope | Garrett Serviss

Take in hand, then, the ephemeris for the year of your birth and read this chapter with it in view.
Astrology | Sepharial
Possibly the Latin ephemeris was the work of Septimius himself.
Encyclopaedia Britannica, 11th Edition, Volume 8, Slice 4 | Various

British Dictionary definitions for ephemeris

ephemeris

/ (ɪˈfɛmərɪs) /

nounplural ephemerides (ˌɛfɪˈmɛrɪˌdiːz)

a table giving the future positions of a planet, comet, or satellite
an annual publication giving the positions of the sun, moon, and planets during the course of a year, information concerning eclipses, astronomical constants, etc

obsolete a diary or almanac

Origin of ephemeris

C16: from Latin, from Greek: diary, journal; see ephemeral

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

Scientific definitions for ephemeris

ephemeris

[ ĭ-fĕm′ər-ĭs ]

Plural ephemerides (ĕf′ə-mĕr′ə-dēz′)

A table giving the coordinates of a celestial body at specific times during a given period. Ephemerides can be used by navigators to determine their longitude while at sea and by astronomers in following objects such as comets. The use of computers has allowed modern ephemerides to determine celestial positions with far greater accuracy than in earlier publications.

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