Meaning : The lowest level of the ocean to which light can reach.
Meaning : The ambiguous region between two categories or states or conditions (usually containing some features of both).
Example :
But there is still a twilight zone, the tantalizing occurrences that are probably noise but might possibly be a signal.
In the twilight zone between humor and vulgarity.
In that no man's land between negotiation and aggression.
Synonyms : no man's land