ephemeris

/ɪˈfɛməɹɪs/

//ɪˈfɛməɹɪs// noun

"ephemeris" is a 9-letter English headword indexed on PlainSpell.

The verdict

“ephemeris” is uncommon English (frequency #86,248 among 2,246 “E” headwords), classed as a noun. The kind of spelling people second-guess.

#86,248
frequency rank, English
2,246
“E” headwords

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - A journal or diary.

Corpus desk

Index EN-ephemeris · ephemeris · English

ephemeris · rank #86,248 · 0 variants · 0 confusables

  • FREQ-RARE #86,248
  • LEN-LONG 9 letters
  • VOW-4 4 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-MID 2,246
  • PHOTO-FINISH envying

Nearest frequency peer: envying (-1 rank slots)

Read with this headword: Spelling guide for this pattern

Desk codes from Wiktionary headword shape, FrequencyWords rank tier, confusable-pair count, generated misspelling depth, letter-cohort book size, and photo-finish peer. Not a difficulty grade.

Long-tail ranks near “ephemeris”

Sparse band: bars invert rank so rarer forms read shorter

corpus weight

What this shows Long-tail view: where “ephemeris” sits against similarly uncommon English ranks.

Source FrequencyWords open word-frequency list As of September 3, 2026
Key facts for ephemeris
PropertyValue
Headwordephemeris
LanguageEnglish
Part of speechNoun
IPA/ɪˈfɛməɹɪs/
Letters9
Frequency rank#86,248
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “ephemeris” in English

Word frequency stretches from the small set of words we reach for constantly (left) out to the long tail barely used once in a while (right).ephemerisfalls in this rarity band:

#1#100#1K#10K#100K
← used constantlyrarely used →

Ticks step logarithmically, so each one marks a roughly tenfold drop in how often the word turns up. Rare peers in the same band: “envying” (#86,247), “ERU” (#86,251), “engendering” (#86,244). Among 2,246 “E” headwords, “ephemeris” is #86,248. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

ephemeris is uncommon English at frequency #86,248 among 2,246 “E” headwords, classed as anoun, transcribed /ɪˈfɛməɹɪs/. Rarity is why readers land here mid-draft. 3 senses are on record.

ephemeris has no tracked misspelling variants, since its letter pattern doesn't lend itself to common typo substitutions. Our dataset records no confusable match here, which usually means its spelling is distinct enough that readers don't reach for a similar-looking word instead.

Etymologically, the entry records: From New Latin ephēmeris, from Ancient Greek ἐφημερίς (ephēmerís, “diary, calendar”), from ἐφήμερος (ephḗmeros, “daily”). The correct English form is ephemeris, spelled E-P-H-E-M-E-R-I-S.

Definition

  1. 1
    A journal or diary.
  2. 2
    A table giving the apparent position of celestial bodies throughout the year; normally given as right ascension and declination.
  3. 3
    Computer software that calculates the apparent position of celestial bodies.

Recorded use

Wiktionary examples

These source excerpts show how ephemeris appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.

  1. 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. […]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.

Etymology

From New Latin ephēmeris, from Ancient Greek ἐφημερίς (ephēmerís, “diary, calendar”), from ἐφήμερος (ephḗmeros, “daily”).

This word in other languages

Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.

Frequently Asked Questions

How do you spell "ephemeris"?
"ephemeris" is spelled E-P-H-E-M-E-R-I-S. The IPA pronunciation is /ɪˈfɛməɹɪs/.
What does "ephemeris" mean?
As a noun, "ephemeris" means: A journal or diary.
How do you pronounce "ephemeris"?
The IPA (International Phonetic Alphabet) transcription for "ephemeris" is /ɪˈfɛməɹɪs/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What is the origin of the word "ephemeris"?
From New Latin ephēmeris, from Ancient Greek ἐφημερίς (ephēmerís, “diary, calendar”), from ἐφήμερος (ephḗmeros, “daily”). See the full etymology section above for more details.
Is PlainSpell free to use?
Yes, PlainSpell is a completely free word reference. You can look up definitions, pronunciations, confusable pairs, homophones, and spelling corrections across 5 languages without any sign-up or subscription.

Similar English words by spelling shape

Same letter count and similar misspelling depth for "ephemeris", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 9 letters (nearest by frequency rank).

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list