The Collaborative International Dictionary
Helvetian
Helvetian \Hel*ve"tian\, a. Same as Helvetic. -- n. A Swiss; a Switzer.
Douglas Harper's Etymology Dictionary
Helvetian
"Swiss," 1550s, from Helvetia terra, Medieval Latin name of Switzerland, from Latin Helvetius "pertaining to the Helvetii," a Celtic people of ancient Gallia Lugdunensis.
Usage examples of "helvetian".
After Caesar sent the Helvetii back to their old lands six years ago, he allowed the Helvetian sept of the Boii to remain in Gaul on the petition of the Aedui, who wanted them as a buffer between Aedui and Arverni.
We had a saying that those in Helvetia had best do as the Helvetians do, though all they generally did was freeze.
When Caesar was in Gaul, he found the Helvetians preparing to go they knew not whither, and put a stop to their motions.