Easton's Bible Dictionary (1897)
The Eulaus of the Greeks; a river of Susiana. It was probably the eastern branch of the Choasper (Kerkhan), which divided into two branches some 20 miles above the city of Susa. , between the two streams of the divided river.
Smith's Bible Dictionary (1863)
(pure water) is mentioned by Daniel, (Daniel 8:2,16) as a river near to Susa, where he saw his vision of the ram and the he-goat. It has been generally identified with the Eulaeus of the Greek and Roman geographers, a large stream in the immediate neighborhood of that city. The Eulseus has been by many identified with the Choaspes, which is undoubtedly the modern Kerkhah, an affluent of the Tigris, flowing into it a little below Kurnah . Recent surveys show that the Choarspes once divided into two streams about 20 miles above Susa. The eastern was the Ulai.
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
), a river of Susians, on whose banks Daniel saw his vision of the ram and he-goat. Dan 8:2-16. It is doubtless the Eulaeus of the Greeks and Romans, a large stream in the vicinity of Susa (Shushan). Recent explorations have shown that the river Choaspes (Kerkhan) divides about 20 miles above Susa. The eastern branch, which received the Shapur and fell into the Karan, was probably the Ulai. This bifurcation of the stream explains the otherwise difficult passage, "I heard a man's voice between the banks of Ulai," Dan 8:16 - that is, between the banks of the two streams of that divided river.
Hitchcock's Bible Names (1869)
strength; fool; senseless