σάκκος

a sack, a receptacle for holding or carrying various things, as money, food, etc., a course cloth, a dark course stuff made especially from the hair of animals, a garment of the like material, and clinging to the person like a sack, which was wont to be worn (or drawn over the tunic instead of the cloak or mantle) by mourners, penitents, suppliants and also by those who like the Hebrew prophets, lead an austere life