Danube
"Danube" is an Old European river name derived from a Proto-Indo-European "*dānu". Other river names from the same root include the Dunaj, Dzvina/Daugava, Don, Donets, Dnieper, Dniestr, Dysna, Tana and Tuoni. In Rigvedic Sanskrit, "dānu" means "fluid, drop", in Avestan, the same word means "river". In the Rigveda, "Dānu" once appears as the mother of Vrtra, "a dragon blocking the course of the rivers." The Finnish word for Danube is Tonava, which is most likely derived from the word for the river in Swedish and German, "Donau". Its Sámi name "Deatnu" means "Great River". It is possible that "dānu" in Scythian as in Avestan was a generic word for "river": "Dnieper" and "Dniestr", from "Danapris" and "Danastius", are presumed to continue Scythian "*dānu apara" "far river" and "*dānu nazdya-" "near river", respectively.
Alb-Donau-Kreis
The district is named after the Danube River (German "Donau") and the Swabian Alb ("Schwäbische Alb") mountains. The Danube enters the district in the southwest, runs through the southern parts of the district and leaves eastwards to Ulm. North of the Danube banks the hills of the Swabian Alb rise. The hill chain extends from southwest to northeast parallel to the course of the Danube River and is continued on either side of the district. An affluent of the Danube, the Iller River, forms the southeastern border of the Alb-Donau district, before it meets the Danube in Ulm.