Dunăre.

Probably ultimately from Latin Danuvius/Danubius, though through an uncertain intermediate form. A form *Donaris has been proposed to be the one that preceded the Romanian word, possibly showing influence from an older paleo-Balkan or Thracian name for the river, as the -aris suffix can be found in another river, Naparis. The Latin term is likely derived from a Proto-Celtic *Dānowyos, from *Dānu, of Indo-European origin. Doublet of Danubiu. Alternately, it may have been borrowed from Old Church Slavonic Дꙋнавъ (Dunavŭ), Доунавъ (Dunavŭ), from Proto-Slavic *Dunavь, from Gothic *𐌳𐍉𐌽𐌰𐍅𐌹 (*dōnawi), with a singular form recreated from earlier plural form Dunări, from *Duna, akin to Aromanian Duna. Ultimately from Proto-Indo-European *déh₂nu (“river goddess”), akin to *dʰenh₂- (“to set in motion; to flow”). Likely found in many other river names such as Doncaster, Don, Donets and Dniester, perhaps by way of Scythian (compare Ossetian дон (don, “river”)) or Celtic.