Source : Webster's Revised Unabridged Dictionary (1913)

Jungle \Jun"gle\, n. [Hind. jangal desert, forest, jungle; Skr.
   ja?gala desert.]
   A dense growth of brushwood, grasses, reeds, vines, etc.; an
   almost impenetrable thicket of trees, canes, and reedy
   vegetation, as in India, Africa, Australia, and Brazil.

Source : WordNet®

jungle
     n 1: an impenetrable equatorial forest
     2: a location marked by an intense competition and struggle for
        survival
     3: a place where hoboes camp [syn: {hobo camp}]