User blog comment:Gsimenas/Volume 8 Yen Press naming/@comment-28251580-20160828101837/@comment-28251580-20160905203950

@OD: The German Duden doesn't know it, and the only(!) one reference is in Grimm's Fairy Tales as kopper. Even if it's Old German, nobody knows the meaning of this word without the sentence from the book. But this discussion should be held off-topic, my vote still goes to Coper as the main article