Before this past weekend, I'd never heard Easter called Resurrection Sunday. I heard it twice on the weekend shows, once from a conservative Republican in Congress, and once from a centerist Democrat in Congress. The latter, an African American Congressman from South Carolina, said off hand "we're supposed to call it Resurrection Sunday now".
I don't like it.
Apparently, what this relatively newly coined word is, is part of a widely held angst that everything on the liturgical calendar might have some pagan origin. This is silly.
The classic one is that Christmas falls on top of a Roman holiday, which is particularly odd given that the Roman holiday so noted first came into existence after the first Christian texts noting the celebration of Christ's Mass in December. The deal with Easter, apparently, is a fear that it is tied to the northern European goddess Eostre, who was the goddess of fertility and the goddess of the dawn. People like to say that this is "German", but in actuality it would be Norse, with the Anglo-Saxons having close connections with the Scandinavians even before they became illegal immigrants on Great Britain. The Venerable Bede made that claim, and he lived from 672 to 735, so in relative terms he was sort of close, but not all that close, to when the Angles, Saxons and Jutes had first shown up.
Bede further claimed that British Christians, using the Saxon calendar, starting calling Easter by that name as it occured in Eosturmonath (April) or Eastermonað. If so, it also helps explain Easter eggs and the Easter Bunny, although it wouldn't explain why a bunny would leave boiled eggs all over, or why Easter Eggs are so famously associated with the East, as in Ukraine and Russia, either.
That the egg custom is really old and seems to ahve been adopted from a Persian Nowruz tradition actually would serve to explain the eggs. . . The tradition was old by the time it showed up on Great Britain.
The Easter Bunny is more obscure. Rabbits had no association with Eostre, however. About all we really know about the Easter Bunny is that it was a German Lutheran custom, and originally it played the role of a judge, evaluating whether children were good or disobedient in behavior at the start of the season of Eastertide, making the rabbit sort of scary.
Back on topic, and be all that as it may, some believe that the word Easter comes from an old Germanic, in this in context it would be Low German, probably Saxon, word for "east" which also, if fully extended to "Easter" grammatically meant to turn to the east. When the etymology is really examined, this is in fact the most likely explanation. Some who have looked at it go further and claim that the word came from a Latin loan word (of which there are a surprising number in German), that being Auster, which sounds a lot like Easter, but actually had sort of a complicated meaning, the most simple being south, but the word apparently having other more complicated implications associated with the dawn. However, some would say, including me, that instead Auster and East have the same Indo-European root word, that being *h₂ews-, which means ‘dawn’, with the sun rising, of course, in the East. Those people claim the Germanic East is a variant of the root *h₂ews-ro-, whereas Auster is the Italic reflex, from *h₂ews-teros. And it goes from there.
The latter sounds complicated, but this too is more common than we imagine. Certain elemental Indo-European words have ended up in all the Indo-European languages, twisted and turned over the millennia, which all make sense if their roots are explained, but which don't seem to when you first hear them. Indeed, there's the added odd widely observed phenomenon that certain words in other languages that depart widely from your native language, almost instantly make sense when you hear them, an example being Fenster, the German world for "window", which is fenestra in Latin and fenêtre in French. Just my hypothesis on the latter, but it's like because of some deep Indo-European root that we otherwise understand.
Anyhow, for what it is worth, as Americans tend to believe that things are uniquely centered around us, the German word for Easter is Ostern. I note this as I've seen repeated suggestions that only in English is the word "Easter" used. This isn't true. Ostern, which has the distinct "Ost", or "East" in it, is pretty close, suggesting that the directional origin of the name is correct. I.e., in German Ostern derives from the Ost, the German word for East.
Likewise, the Dutch, who speak a closely related Germanic language, call the day Ooster. The Dutch word for East is Oosten. So here too, the Dutch word for Easter derives from the Dutch word for East.
Applying Occam's Razor, and keeping in mind that English is a Germanic language related to German and Dutch (Dutch more closely), leads us to the conclusion that the word "Easter" derives from the cardinal direction East, particularly when the cousin Germanic languages of German and Dutch are considered, which they usually are not. Once that is done, and it is realized that at about the time the word Easter was first used all the northern German languages were much closer to each other than they are now, and they are still pretty close, logic pretty much dictates this result.
Most language groups do not, however, call Easter that. The word seems to behave the way German words did and do, and has "East" as its major component, hence "East"er, "Ost"ern and Ooster.
The Scandinavian goddess explanation is considerably more complicated in every fashion.
Most non-Germanic language speakers, and some Germanic language speakers, don't use a word anything like this, of course.
Latin and Greek, with together with Araamic, would have had the first word for the Holy Day, and they have always called Easter Pascha (Greek: Πάσχα). That is derived from Aramaic פסחא (Paskha), cognate to the Hebrew פֶּסַח (Pesach), which is related to the Jewish Passover, all of which makes both linguistic, historic, and religious sense, although in the latter case one that causes some irony as we'll explain below. Pascha actually shows up in English in at least Catholic circles, as the term Paschal is given frequent reference in relation to the Last Supper, but also beyond that in relation to Easter.
Of interest, the Swedish word for Easter is Påsk, the Norwegian Påske, the Danish Påske and the Icelandic Páskar. If the word derived from a Scandinavian goddess, we'd expect the same pattern to hold in Scandinavia, which was the origin point of Eostre, although that would not obviously be true. Instead, in all of Scandinavia, the word derives from Pascha.
The Frisian word for Easter is Peaske, which is particularly interesting as Frisian is extremely closely related to English and some people will claim, inaccurately, that it's mutually intelligible. Peaske is obviously from Pascha, but it's almost morphed into Easter, which could cause some rational explanation if Easter is just a badly mispronounced Peaske. Wild morphing of words can occur, as for example the Irish Gaelic word for Easter derives from Pascha, but is Cháisc, which wouldn't be an obvious guess.
Given the German and Dutch examples, however, the Frisian word almost certainly doesn't suggest that Easter came from Pascha.
The use of Pascha makes sense, as every place in Western Europe was Christianized by the Latin Rite of the Church, which would have used a Latin term for the Holy Day. The difference is, however, they weren't all Christianized at the same time. The Anglo-Saxons encountered Christianity as soon as they hit the British shores in the 400s, probably around 449. At that time, most of the residents of the island were British or Roman Christians, and they would have sued the Latin term. Conversion of the invaders is, however, generally dated to the 600s.
The Scandinavians were however much later. Christianity appeared in Scandinavia in the 8th Century, but it really began to make major inroads in the 10th and 11th Centuries. When the Church sent missionaries to the Saxons, it remained a much wilder place than it was to be later. Scandinavia was very wild as well, in the 10th and 11th Centuries, but Scandinavian roaming was bringing into massive contact with the entire Eastern and Wester worlds in a way that sort of recalls the modern impact of the Internet. They changed quickly, but they were, ironically, more globalist and modern than the Saxons had been a couple of centuries earlier. They also became quite devout, contrary to what Belloc might imagine, and were serious parts of the Catholic World until the betrayal of Gustav Vasa.
But here's the added thing. What if, in spite of the lack of evidence, the day's name in English recalls Eostre or Eosturmonath (Eastermonað"? So what?
Well, so what indeed. It really doesn't matter.
Early Greek and Aramaic speaking Christians took their term for the day from Passover, or rather פֶּסַח (Pesach). So they were borrowing a Jewish holiday for the name right from the onset. Nobody seems to find this shocking or complain about it. As far as I know, Jews don't complain about it. It simply makes sense.
And borrowing holidays that preexist and even simply using the dates is smart. The date of Easter doesn't fit this description at all, but if the word does, borrowing it would have been convenient if a holiday existed that was celebrating rebirth. Explaining concepts through the use of the familiar is a smart thing to do, and indeed in the US this has been done with a civil holiday, Cinco de Mayo, which Americans inaccurately believe is a Mexican holiday celebrating Mexican independence, and which have made the We Like Mexico holiday.
So, if Eostre had a day, or if the day in Saxon was named after the month named after her, it really doesn't matter.
Indeed, on that latter note, we've kept the Norse goddess Frig in Friday, the Norse God Thor, in Thursday, and the Norse God Woden in Wednesday., in English, and we don't freak out about it. Sunday originally honored the Sun, and we don't find Evangelical's refusing to use the word Sunday, as it's also the Christian Sabbath
So what of Resurrection Sunday?
I'm blaming Oliver Cromwell, fun sucker.
Great Britain's experience in the Reformation was nearly unique, in some ways. Really radical Protestant movements, such as the Calvinists, took root in some places on the European continent, but by and large they waned, leaving isolated, for the most parts, pockets in areas in which they were otherwise a minority. Looked at from a distance, the initial round of Protestant "reformers" didn't seek to reform all that much. Luther continued to have a devotion to the Blessed Virgin, and Lutheran services today look pretty Catholic.
In England, however, official religions whipped back and forth. King Henry VIII didn't want a massive reform of theology, he wanted to instead control the Church, but things got rapidly out of hand. After him, the Church of England struggled between being very Catholic in outlook and being a "reformed" church.
Cromwell came up as a childhood beneficiary of the theft of Church property in the form of the dissolution and appropriation of the monasteries. He evolved into being a radical sola scriptura Calvinist and saw the suppression of the Catholic and Anglican Churches come about. Under his rule, religious holidays were made illegal under the theological error of sola scriptura. After his death, the English Restoration brought a lot back, but it was never able to fully bring back in Calvinist who had adopted a rather narrow provincial English, or Scottish, view of their Christian faith, filtered through the language that they spoke. They heavily influenced Christianity in the Americas, and their influence continues to carry on, which explains how they can adopt a view that ignores the other Germanic languages and which, in seeking to give a new term to Easter, ignores the fact that the logical choice would be the Aramaic word פסחא (Paskha) which would appear in the Bible as it would have applied to Passover, or the Greek word Πάσχα, Páscha, which means Easter and Passover. So modern Evangelicals have inherited the Puritan narrow focus, ignored the other Germanic language words, and ignore the original Greek and Aramaic ones, in order to come up with a new one with no history of use whatsoever.
Let's just stick with Easter.