Fun fact: according to the etymology I could find online it's actually originally a German word (meaning client of a prostitute) that was borrowed by Yiddish, then borrowed in turn by Polish from Yiddish and also ended up in a couple of other European languages.
Not exclusively. It has elements from Hebrew and Aramaic (of course) as well as from various Slavic languages. A big chunk of it derives from High German but not all.
