Rhaetian (n.) Look up Rhaetian at Dictionary.com
c. 1600, from Latin Rhætia, ancient name of a district in the Alps and of a Roman province between the Rhine, Danube, and Po; from Rhaeti, Raiti, name of a native people. Hence Rhaeto-Romanic (1867), Rhaeto-Romance, language of the Tyrol and southern Switzerland.