twilight zone

Short definition from Wiktionary

Noun

1. 1
   A moving line that divides the daylit side and the dark night side of a planetary body.
2. 2
   A region or context located in between others and therefore not subject to their norms.
3. 3
   A deteriorating area surrounding a central business district.
4. 4
   Synonym of mesopelagic zone (“The part of the ocean where there is very minimal light, located below the photic epipelagic zone but above the aphotic bathypelagic zone.”).
5. 5
   A region in which surreal, supernatural, or fantastic events occur.

Verb

1. 1
   To put or place into an indeterminate position; to be in an ambiguous, undetermined, or improper context.
2. 2
   To cause to daydream or zone out; to cause to lose attention to one's surroundings.
3. 3
   To experience or perceive something bizarre or fantastic.
4. 4
   To behave or occur in a confusing or unexpected manner.