On New Year’s Eve, like people all over the world, Germans wish each other a Happy New Year (Frohes Neues Jahr).
But they also like to proclaim “Guten Rutsch!”
While the direct translation of this popular end-of-year saying would, indeed, be something along the lines of “good slide”, it is actually most likely derived from entirely different origins steeped in Jewish tradition.
Many linguists claim that this traditional New Year’s Eve expression in German has nothing to do with “sliding” (rutschen) into the New Year, even though most Germans now understand it that way.
It is actually the “corruption” of a phrase adopted from Jews wishing each other a “Guten Rosh” – the word “rosh” in Hebrew means “head” or “beginning,” hence the beginning of a new year.
The expression could thus have come into German via the Yiddish for “a good beginning” – as in “Rosh Hashanah,” the Jewish New Year.
And that would make it just one of many German (and English) expressions that come from Yiddish.