...("good slide"), that's what my German friends—and some Americans who knew enough German—wished me for New Year's Eve. I always thought the phrase referred to the fact that snow or ice may be on the road at that night or that most Germans moved through it in an alcoholic daze. But John Dingly (thanks, John!) pointed out to me that Rutsch, in that context, is most likely a piece of folk etymology that derives, via Yiddish, from Hebrew rosh ("beginning"), as in Rosh-ha-Shana.
Grammatical note: Guten Rutsch is the accusative (direct object case) of guter Rutsch. Why do Germans not use this nominative? Because Guten Rutsch is short for Ich wünsche dir/euch/Ihnen einen guten Rutsch (I wish you a good slide), where (einen) guten Rutsch is the direct object. The same holds BTW for Guten Morgen, Guten Tag, Guten Abend (Good Morning, G'Day, Good Evening).
Evolutionary semantics
1 hour ago