Ephemeris
noun ·Uncommon ·Advanced level
Definitions
- 1 A journal or diary. obsolete
"Wee heard the King was solacing at the Caspian Sea, whither now wee are travelling. Till then let us keepe an Ephemerides or day-journey."
- 2 an annual publication containing astronomical tables that give the positions of the celestial bodies throughout the year wordnet
- 3 A table giving the apparent position of celestial bodies throughout the year; normally given as right ascension and declination.
"[…]Mr. Samuel got 150 pounds of bread, with a small quantity of rum and wine, also a quadrant and compass; but he was forbidden on pain of death to touch either map, ephemeris, book of astronomical observations, sextant, timekeeper, or any of my surveys or drawings."
- 4 Computer software that calculates the apparent position of celestial bodies.
Example
More examples"Utilizing an ephemeris, an astronomer can calculate lunar phases and the times of rising and setting of the sun and of the moon all around the world and for any day of the year."
Etymology
From New Latin ephēmeris, from Ancient Greek ἐφημερίς (ephēmerís, “diary, calendar”), from ἐφήμερος (ephḗmeros, “daily”).
Related phrases
More for "ephemeris"
Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.