It's the early middle ages, and you and your friends are putting together your Fantasy Language Teams when a three-way deal starts to suggest itself. You're playing Old English, but your word
eagðyrl, just hasn't been scoring the usage you'd hoped. You look over to Old Norse and see the word
vindauga, who's languishing where he is, but you think, with a little retooling, a little training, he could have a place on your team and really become a household name.
Meanwhile, Team Norse is looking to replace
vindauga with something else, but they're not interested in your
eagðyrl. They're more interested in the Romance player
fenestra.
Fenestra's all the rage: he'll end up winning the Vocabulary League's highest prize--the Import Cup--both in France as
fenêtre and in Germany as
Fenster.
So what can you, Old English, give to Old High German or Old French to persuade them to send
fenestra north, thereby allowing Norse to release
vindauga? Well, there were many borrowings throughout history, but to pick one, let's go with
Sonnabend. (You don't have to trade for the same position, after all.) The day before Sunday has several names among Germanic lands. One of the German words,
Samstag comes from
sabbath. If you say
Samstag with a cold, you'll hear the inherent relationship between b's and m's: hence sabb[ath]'s Day > sab's Tag > Samstag.
In England, the day's dedication to pagan Saturn prevailed in the name Saturday--an irony, since the Christian missionaries to the continent preferred 'Sun-eve', or
sunnanæfen, cognate of what would become the other German word for Saturday,
Sonnabend. So the English word is Roman-influenced, but the German word is Old English.
<aside>Note that German did already have the Germanic roots for sun and eve. Strictly speaking, this isn't a word borrowing, but a borrowed translation. Case in point: The telephone allows you to hear things far away, hence its name from Greek
tele-, far, and
phoné, sound. The English word is put together from words borrowed from Greek. But German puts its word together from native Germanic roots:
Fernsprecher =
fern, far +
sprecher, speaker. The same thing applies to
Sonnabend: native (German) roots, influenced by Old English construction (
sunnan + æfen >
Sonn + Abend).</aside>
Anyway, with the contribution of OE
sunnanæfen to German
Sonnabend we can call our three-way Fantasy trade complete.
Fenestra goes to Team Norse where it will become, e.g., Swedish
fönster. Norse
vindauga, literally 'wind-eye', comes to Old English where it will become
window. OE
eagðyrl is cut from the team. And Old English sends
sunnanæfen to German where it becomes a household name every week as
Sonnabend.
Bottom line: no one kept their original word for 'window', except possibly Old French. German and Norse took the Romance root. English has a Germanic root, but not the original Old English one. And while French kept the Romance root, it has plenty of words of Germanic origin as well (matter for another post some day).