Niente is an Italian equivalent of the Yiddish word "bupkus." Specifically, the Yiddish word means "nothing, nothing at all." The Italian word literally means "nothing." The pronunciation is "NYEHN-teh."
No, some Jewish people speak Hebrew and/or Yiddish. It is important to note that the Yiddish word for Jewish is Yiddish, so the language is actually called "Jewish", but there is no language identified with the English word "Jewish".