Mesopotamian river, arising in Armenia and flowing to the Persian Gulf, Old English Eufrate, from Greek Euphrates, from Old Persian Ufratu, perhaps from Avestan huperethuua "good to cross over," from hu- "good" + peretu- "ford" (from PIE root *per- (2) "to lead, pass over"). But Kent says "probably a popular etymologizing in O.P. of a local non-Iranian name" ["Old Persian," p.176]. In Akkadian, purattu. Related: Euphratean.