Dīs Pater was commonly shortened to simply Dīs. This name has since become an alternative name for the underworld or a part of the underworld, such as the City of Dis of The Divine Comedy, which comprises Lower Hell.
It is often thought that Dīs Pater was also a Celtic god. This confusion arises from the second-hand citation of one of Julius Caesar's comments in his Commentaries on the Gallic Wars VI:18, where he says that the Gauls all claimed descent from Dīs Pater. However, Caesar's remark is a clear example of interpretatio Romana: what Caesar meant was that the Gauls all claimed descent from a Gaulish god that reminded him of the Roman Dīs Pater, that is, a chthonic deity associated with prosperity and fertility. Different possible candidates exist for this role in Celtic religion, such as Gaulish Sucellus, Irish Donn and Welsh Beli Mawr, among others.
In De Natura Deorum, Cicero derives the name of Dīs Pater from dives, suggesting a meaning of "father of riches", directly corresponding to the name Pluto (from Greek Πλούτων, Ploutōn, meaning "wealthy"). According to some 19th century authors, many of Cicero's etymological derivations are not to be taken seriously, and may indeed have been intended ironically; however, this particular derivation of Cicero's has been accepted by some contemporary authors, some even suggesting that Dīs Pater is a direct loan translation of Ploutōn.
Like Pluto, Dīs Pater eventually became associated with death and the underworld because the wealth of the earth—gems and precious metals—was considered in the domain of the Greco-Roman underworld. As a result, Dīs Pater was over time conflated with the Greek god Hades.