We don't have synonyms for helvetic yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are hermetic, heretic and hellenic.
(adj) :
Of or pertaining to the Helvetii, the ancient inhabitants of the Alps, now Switzerland, or to the modern states and inhabitant of the Alpine regions.
(adj) :
Of or pertaining to the Helvetii, the ancient inhabitants of the Alps, now Switzerland, or to the modern states and inhabitant of the Alpine regions.