/un"deuhr werrld'/ , n.
1. the criminal element of human society.
2. the imagined abode of departed souls or spirits; Hades.
3. a region below the surface, as of the earth or a body of water.
4. the opposite side of the earth; the antipodes.
5. Archaic. the earth.
[ 1600-10; UNDER- + WORLD ]