tithed fields, or fields granted on a tithe, as appears from Tacitus, to the rabble of Gauls who succeeded the Marcomanni, who had till then proved a check to the Roman conquests up the Rhine; and hence probably their name, which signifies people living on the marches or limits of the empire. In Cicero we meet with Ager Decumans, which is of the same import with the Ager Decumans of Tacitus.