ti'-gris (Tigris, the Greek equivalent of the Hebrew chiddeqel): One of the rivers of Eden going "eastward to Assyria" (Genesis 2:14 margin), called the Great River (Daniel 10:4), elsewhere mentioned in the apocryphal books, as in Tob 6:1; Judith 1:6; Ecclesiasticus 24:25, called Diglath in Josephus, and Diglit in Pliny, now called in Mesopotamia Dijleh, generally supposed to be a Semitic corruption of Tigra, meaning originally an arrow, which from its rapidity of motion is symbolized. The Tigris rises in the mountains of Armenia, latitude 38 degrees 10 minutes, longitude 39 degrees 20 minutes, only a few miles from the main branch of the Euphrates. After pursuing a tortuous southeasterly course for 150 miles, it is joined by the east branch at Osman Kieui, some distance below Diarbekr. Here the stream is 450 ft. wide and 3 or 4 ft. deep. Passing through numerous mountain gorges for another 150 miles, it emerges into the region of low hills about Nineveh, and a little below into the great alluvial plain of Mesopotamia. Thence in its course to Bagdad it is joined by the Great Zab, the Lesser Zab, the Adhem, and the Diyaleh rivers, bringing a large amount of water from the Zagros Mountains. At Bagdad the overflows from the Euphrates in high water often increase the inundations. The flood season begins early in the month of March, reaching its climax about May 1, declining to its natural level by midsummer. In October and November, the volume of water increases considerably, but not so much as to overflow its banks. Below Bagdad, throughout the region of Babylonia proper, the Tigris joins with the Euphrates in furnishing the water for irrigation so successfully used in ancient times. English engineers are at present with great promise of success aiming to restore the irrigating systems of the region and the prosperity of ancient times. The total length of the river is 1,146 miles. It now joins the Euphrates about 40 miles Northwest of the Persian Gulf, the two streams there forming the Shat el Arab, but in early historical times they entered the Persian Gulf by separate mouths, the Gulf then extending a considerable distance above the present junction of the rivers, the sediment of the streams having silted up the head of the Gulf to that distance.