Easton's 1897 Bible Dictionary:

Engedi
   fountain of the kid, place in the wilderness of Judah (Josh.
   15:62), on the western shore of the Dead Sea (Ezek. 47:10), and
   nearly equidistant from both extremities. To the wilderness near
   this town David fled for fear of Saul (Josh. 15:62; 1 Sam.
   23:29). It was at first called Hazezon-tamar (Gen. 14:7), a city
   of the Amorites.

     The vineyards of Engedi were celebrated in Solomon's time
   (Cant. 1:4). It is the modern 'Ain Jidy. The "fountain" from
   which it derives its name rises on the mountain side about 600
   feet above the sea, and in its rapid descent spreads luxuriance
   all around it. Along its banks the osher grows abundantly. That
   shrub is thus described by Porter: "The stem is stout, measuring
   sometimes nearly a foot in diameter, and the plant grows to the
   height of 15 feet or more. It has a grayish bark and long oval
   leaves, which when broken off discharge a milky fluid. The fruit
   resembles an apple, and hangs in clusters of two or three. When
   ripe it is of a rich yellow colour, but on being pressed it
   explodes like a puff-ball. It is chiefly filled with air...This
   is the so-called 'apple of Sodom.'" Through Samaria, etc. (See APPLE.)


Hitchcock's Bible Names Dictionary (late 1800's):

En-gedi, eye, or fountain, of the goat, or of happiness