High Holy Days

What is the origin of the phrase High Holy Days, as opposed to the more accurate translation "Awesome Days"?

I spoke to several people who are knowledgable about language, and came out with the following information. German uses the phrase "Hohe Feiertage", which means "high celebration days". Yiddish, interestingly, does not appear to have any similar phrase in it - nor do any other languages, to the knowledge of my source, have equivalent terminologies referring to the yamim nora'im. Hence, the phrase most likely jumped over from German, but the origins of the phrase are still unclear.