Learning about the origin of English names for days of the week, I found it curious that some of them had an original meaning borrowed from Latin, but the words themselves were a translation. So Monday comes from Latin "Lunæ dies", which means day of the moon, which then got translated using the old English/Germanic word for moon "mona", eventually giving rise to the word Monday.

If the Latin influence was strong enough to supply the original meaning for the word, then why didn't they simply borrow the actual Latin word instead of translating it into the Germanic equivalent? In other words, why didn't we end up with something like "Lunday"?

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    Because nothing in English is from English. The days of the week were mostly "borrowed" from Germanic.
    – Hot Licks
    Feb 16, 2016 at 18:21
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    I would guess that it's because the names themselves aren't derived from Latin, just the idea of naming them after the astrological planets, so 'Sun-day', 'Moon-day', and 'Saturn-day'. Notice that English has lost the other four, replacing them with the names of Norse/Germanic deities.
    – jamesqf
    Feb 16, 2016 at 18:25
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    @TimLymington According to etymonline.com it's a "loan-translation of Late Latin Lunæ dies, source of the day name in Romance languages". I'm in no way an expert, just a curious individual, so if my assumptions are incorrect, I would consider that an answer to my question.
    – ivanatpr
    Feb 16, 2016 at 18:40
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    Only 3 English day names could have meanings borrowed from Latin - Saturday, Sunday, and Monday, named after the "planets" Saturn, Sun, Moon. The others take meanings from names of Norse gods. In French, 6 have names from planets. To recreate the order of planets as it appears in day names, list the planets in reverse order of apparent motion (Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon), and name each hour after a planet in this order, starting with Sun, so the 1st hour of Sunday is named after Sun, the 2nd after Venus, etc. The 1st hour of each day then gives the planet for that day.
    – user160717
    Feb 16, 2016 at 20:12
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    Or since in modular arithmetic 24 is congruent to 3 (mod 7), just start at Sun and keep counting 3 places along the cycle (Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon). So you get Sun (Sunday), Moon (Monday), Mars (Mardi), Mercury (Mercredi), Jupiter (Jeudi), Venus (Vendredi), Saturn (Samedi).
    – user160717
    Feb 16, 2016 at 20:22

3 Answers 3


Between the 1st and 3rd centuries, the Roman Empire gradually replaced their previous system with a 7-day week with each day named after the planets of Hellenistic Astrology: The Sun, The Moon, Mercury, Venus, Mars, Jupiter and Saturn.

When the Germanic culture came in contact with the Romans, there was a practice where Germanic deities were identified with Roman equivalents. This process was known as Interpretatio germanica.

The Germanic peoples adapted the 7-day week system from the Romans and substituted the Roman gods with Germanic equivalents, except for Saturday, which retained the Roman god's name. This process happened after 200 AD but before the introduction of Christianity to Germanic peoples during the 6th to 7th century.

If the Latin influence was strong enough to supply the original meaning for the word, then why didn't they simply borrow the actual Latin word and instead ended up translating it into the Germanic equivalent?

The answer is likely cultural pride. It's likely the Roman system was adapted for reasons of trade, convenience or war — but would you want to retain the names of the gods of your neighbours/enemies in the days of the week?

In other [words], why didn't we end up with something like "lunday"?

Mēnô was the Germanic moon deity (alternate spellings include Máni, Mōna, Māno,) so that's why dies Lūnae became Mōnandæg in Anglo-Saxon.

Why was Sæturnesdæg the only day that retained the Latin god's name? Probably because there was no Germanic god associated with Saturn.


Although the comments posted beneath the question may may be far more interesting, the general explanation is that English language is (to borrow a phrase from Tennessee Williams) "the bastard son of a bastard." It is the "offspring" of diverse "parents," some of which spent centuries in torrid love affairs, while others merely passed in the night of history.

As evident in its names for the days of the week, English is macaronic, a useful adjective which dictionary.com defines as

  1. composed of or characterized by Latin words mixed with vernacular words or non-Latin words given Latin endings.
  2. composed of a mixture of languages.
  3. mixed; jumbled.

While this may not provide a satisfactory etymological explanation of the origin of each day's name, it nevertheless points out that efforts to explain our strange and various (mixed, jumbled) language in purely logical terms will often lead to frustration.

  • 1
    Macaronic usually describes a composition which alternates between two languages. It is not a descriptor used of a language. en.wikipedia.org/wiki/Macaronic_language
    – TimR
    Feb 16, 2016 at 21:02
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    A better word for this specific case is calque.
    – herisson
    Feb 16, 2016 at 22:04
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    I was going to say that coming up with "macaronic" was a feather in Rob's cap, but I guess not.
    – Hot Licks
    Feb 16, 2016 at 22:46
  • @TimRomano has a valid point. However (not to be too petty) calque is not a better word. Dictionary.com gives it as "a loan translation, especially one resulting from bilingual interference in which the internal structure of a borrowed word or phrase is maintained but its morphemes are replaced by those of the native language." While "Monday" might qualify on some level, other day names don't operate this way. While "Saturday" is the most literally macaronic, I think the principle holds up in the other cases as well.
    – Rob_Ster
    Feb 17, 2016 at 0:55
  • @Rob_Ster: what I meant was that all of the English day names besides Saturday use native Germanic roots (names, in this case) that are equivalent to the Latin names.
    – herisson
    Feb 17, 2016 at 6:38

I think gHoppe answered your question best, but just in case you don't already know the current days used by English-speaking individuals were derived thusly:

From The Old Farmer's Almanac:

Question: Where did the names of the days of the week come from?

Answer: The Babylonians named the days after the five planetary bodies known to them (Tuesday through Saturday) and after the Sun and Moon (Sunday and Monday). This custom was later adopted by the Romans. Emperor Constantine established the seven-day week in the Roman calendar in 321 and designated Sunday and Monday as the first two days of the week. The other weekday names in English are derived from Anglo-Saxon names for gods in Teutonic mythology. Tuesday comes from Tiu, or Tiw, the Anglo-Saxon name for Tyr, the Norse god of war. Tyr was one of the sons of Odin, or Woden, the supreme deity after whom Wednesday is named. Similarly, Thursday originates from Thor, the god of thunder. Friday is derived from Frigga, the wife of Odin, representing love and beauty. Saturday comes from Saturn, the ancient Roman god of fun and feasting.

  • 1
    This has nothing to do with the question I asked
    – ivanatpr
    Mar 30, 2018 at 3:07
  • Sorry, I had originally typed: "I think gHoppe answered your question best, but just in case you don't already know the current days used by English-speaking individuals were derived thusly:" I think when I pasted the latter, this part somehow disappeared. Mar 30, 2018 at 3:14
  • 1
    I restored the sentence that you reported having lost from your original answer, and I added formatting to make it easier to read.
    – Sven Yargs
    Mar 30, 2018 at 4:31

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