I recently stumbled upon the term "mensch" and I was corious how that term made it into English, especially with it's meaning as a really good person, when the related terms also used "über/unter-mensch" are taken from Nietzschean philosophy and the Nazis and seem to have translated well from German, when "Mensch" in German is just a human being without goodness being implied.
Does anybody know how that came about, if the term has seen any changes in its meaning and (if not too big of a request) could shed some light on the more recent intersection between German and English where words were loaned but changed their meaning quite remarkably?
The term "mensch" actually didn't enter the English vernacular through German but through Yiddish, a quasi-Germanic language spoken by Ashkenazi Jews, primarily from Eastern Europe. In Yiddish "menschn" is the word for people. However, "a mensch" has the connotation of someone being a particularly good person, such as in the phrase "meyn Man iz a mensch!" (my husband is a good man). Above a mensch is a Tzaddik which has the connotation of not just a good man, but a spiritually hightened or holy man. There are several phrases which include this word such as "vi a mensch" which means to behave correctly, a common phrasing of this which is particularly common in orthodox Jewish communities is to tell a child to "act/eat/behave like a mensch" as a corrective statement when the child is misbehaving.
The word entered the American English vernacular during the early 1900s when pogroms and increased antisemitism caused a large number of Yiddish speaking Jews to immigrate to America. Yiddish speaking communities became prominent in cities like New York and Chicago. Neighborhoods like Williamsberg and Crown Heights in Brooklyn still have large Yiddish speaking communities. Many slang and vernacular words in American English come from minority communities such as African American, Hispanic American, LGBT, Indigenous communities, and indeed from Jewish communities.