Danubius

• Dānuvius

From Proto-Celtic *Dānowyos, an extended form of the river-name *Dānu, either from Proto-Indo-European *déh₂nu (“river goddess”) or from Proto-Indo-European *dʰenh₂- (“run, flow”).

Dānubius m sg (genitive Dānubiī or Dānubī); second declension

1. The river Danube.
   • Tacitus, Gemanica, chapter 1 (Oxford revised translation)

     Germania omnis a Gallis Rhaetisque et Pannoniis Rheno et Danubio fluminibus.

     Germany is separated from Gaul, Rhaetia, and Pannonia, by the rivers Rhine and Danube.

Second-declension noun, singular only.

¹Found in older Latin (until the Augustan Age).

All descendents are borrowings.