from The American Heritage® Dictionary of the English Language, 4th Edition
- n. An area of ambiguity between two distinct states or conditions: a twilight zone between good and evil.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A region or context located in between others and therefore not subject to their norms.
- n. a region in which surreal, supernatural, or fantastic events occur
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. the ambiguous region between two categories or states or conditions (usually containing some features of both)
- n. the lowest level of the ocean to which light can reach
From the anthology television series The Twilight Zone, first aired in 1959. (Wiktionary)