Easton's Bible Dictionary (1897)
Plain, in the Revised Version of 2 Kings 14:25; Josh. 3:16; 8:14; 2 Sam. 2:29; 4:7 (in all these passages the A.V. has “plain”); Amos 6:14 (A.V. “wilderness”). This word is found in the Authorized Version only in Josh. 18:18. It denotes the hollow depression through which the Jordan flows from the Lake of Galilee to the Dead Sea. It is now called by the Arabs el-Ghor. But the Ghor is sometimes spoken of as extending 10 miles south of the
Dead Sea, and thence to the Gulf of Akabah on the Red Sea is called the Wady el-Arabah.
Smith's Bible Dictionary (1863)
(burnt up). Although this word appears in the Authorized Version in its original shape only in (Joshua 18:18) yet in the Hebrew text it is of frequent occurrence. It indicates more particularly the deep-sunken valley or trench which forms the most striking among the many striking natural features of Palestine, and which extends with great uniformity of formation from the slopes of Hermon to the Elanitic Gulf (Gulf of Akabah) of the Red Sea; the
most remarkable depression known to exist on the surface of the globe. Through the northern portion of this extraordinary fissure the Jordan rushes through the lakes of Huleh and Gennesaret down its tortuous course to the deep chasm of the Dead Sea. This portion, about 150 miles in length, is known amongst the Arabs by the name of el-Ghor . The southern boundary of the (Ghor is the wall of cliffs which crosses the valley about 10 miles south of
the Dead Sea. From their summits, southward to the Gulf of Akabah, the valley changes its name, or, it would be more accurate to say, retains old name of Wady el-Arabah .
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
AR'ABAH (burnt up), a word of frequent use in the Hebrew, though found only once in the English, version. Josh 18:18. It is the name applied to the deep sunken valley which extends from Mount Hermon to the Elamitic Gulf of the Red Sea. This remarkable depression is about 250 miles long, and includes the Sea of Galilee and the Salt, or Dead, Sea, In some passages in Deuteronomy, the plain or "the Arabah" refers to the southern portion of the
valley, between the Salt Sea and the Red Sea, Deut 1:1; Deut 2:8; in other passages the word doubtless refers to the northern portion of that valley along the Jordan, which the Arabs now call el-Ghor. See Jordan. Arabah is now applied only to that portion of the valley which stretches from the chalk-cliffs below the Dead Sea southward to the Gulf of Akabah— Elanitic Gulf. It is about 100 miles long and from 4 to 16 miles wide. The limestone
walls on the west of the valley are from 1500 to 1800 feet in height; the mountain-wall on the east side of the valley rises from 2000 to 2300 in height, and in Mount Hor to 5000 feet, and is chiefly composed of granitic and basaltic rock. The surface of the valley is covered with loose gravel, blocks of porphyry, and is furrowed with torrents, with scarcely a trace of vegetation. It is oppressively hot, is swept with burning winds, the Sirocco
blowing at some seasons without intermission, a region dreary and desolate. The theory that the Jordan once ran through this valley into the Red Sea is now held to be untenable. Arabah in Josh 18:18 has also been mistaken for the name of a city, and confounded with Beth-arabah of Josh 15:61; Josh 18:22; but in v. 1 Sam 30:18 the word has the article before it in the Hebrew, and hence refers to the plain, as elsewhere. See also Zin, Wilderness of,
and Salt Sea.