In his etymology column for the Oxford English Dictionary, Anatoly Liberman at each of these possibilities. He considered ever more improbable origins — Latin for "ribbon"? German for "street"? Latin for "to throw"? — before declaring the word a stubborn mystery.
But whatever the root language, the word's original meaning was clear: "the quarter in a city, chiefly in Italy, to which the Jews were restricted," as the OED puts it. In the 16th and 17th centuries, cities like Venice, Frankfurt, Prague and Rome forcibly segregated their Jewish populations, often walling them off and submitting them to onerous restrictions.
