We don't have synonyms for raetia yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are ratia, retia and rhaetia.
(n) :
(historical) A Roman province bordered on the west by the Helvetii, on the east by Noricum, on the north by Vindelicia, on the west by Cisalpine Gaul and on south by Italy, which occupied the region which is today central and eastern Switzerland, southern Bavaria, most of Tirol and part of Lombardy.
(n) :
(historical) A Roman province bordered on the west by the Helvetii, on the east by Noricum, on the north by Vindelicia, on the west by Cisalpine Gaul and on south by Italy, which occupied the region which is today central and eastern Switzerland, southern Bavaria, most of Tirol and part of Lombardy.