jungle

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Land densely overgrown with tropical vegetation.
2. n. A dense thicket or growth.
3. n. A dense, confused mass; a jumble.
4. n. Something made up of many confused elements; a bewildering complex or maze: sorting through the jungle of regulations.
5. n. A place or milieu characterized by intense, often ruthless competition or struggle for survival: the corporate jungle.
6. n. Slang A place where hoboes camp.

Century Dictionary and Cyclopedia

1. n. A dense growth of rank and tangled vegetation, large and small, often nearly impenetrable, such as is characteristic of some parts of India, especially in the swampy regions at the base of the Himalaya mountains.
2. n. A tract of land covered by such vegetation; a wilderness of dense overgrowth; a piece of swampy thickset forest-land.

Wiktionary

1. n. A large, undeveloped, humid forest, especially in a tropical region, that is home to many wild plants and animals.
2. n. A place where people behave ruthlessly, unconstrained by law or morality.
3. n. A style of electronic music.

GNU Webster's 1913

1. n. 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.
2. n. A place of danger or ruthless competition for survival.
3. n. Anything which causes confusion or difficulty due to intricacy.

WordNet 3.0

1. n. an impenetrable equatorial forest
2. n. a place where hoboes camp
3. n. a location marked by an intense competition and struggle for survival