Arvernus

In Gallo-Roman religion, Arvernus was an epithet of the Gaulish Mercury. Although the name refers to the Arverni, in whose territory Mercury had at important sanctuary at the Puy-de-Dôme, all of the inscriptions to Mercury Arvernus are found farther away along the Rhenish frontier. The name is also recorded once as Mercury Arvernorix, 'king of the Arverni'. Compare also the title Mercury Dumiatis ('of the Puy-de-Dôme'), found in the territory of the Arverni.
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[Celtic] The Gallic god of the Arverni.

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Arverni (pl.); (tribe of SE Gaul - in Caesar's Gallic War)