twilight zone

Because such a zone (in the literal sense of the term) is twilit; see twilight § Etymology.

twilight zone (plural twilight zones)

1. (astronomy, astrophysics) A moving line that divides the daylit side and the dark night side of a planetary body.

   Synonym: terminator

   Coordinate term: greyline

2. (by extension) A region or context located in between others and therefore not subject to their norms.

   Synonym: shadowland

   • 1911, Case and Comment:

     As to this right, therefore, the people have expressly created a twilight zone, in which neither nation nor state can act.

   • 1978, Cornelius Cole Smith, Fort Huachuca: The Story of a Frontier Post:

     They were interesting because they represented a sort of twilight zone separating the "old days" from modern times.

   • 1999, Grant Gilmore, Security Interests in Personal Property:

     ...the classification scheme related to goods which lay in a "twilight zone" between consumer goods and equipment or between inventory and farm products.

   • 2006, Charles C Marshall, The Roman Catholic Church in the Modern State:

     But is there not a twilight zone over which both Church and State put forth claims?

3. (geography) A deteriorating area surrounding a central business district.
   • 2012, George Sternlieb, James W. Hughes, Shopping Centers: U.S.A., page 52:

     Geographically speaking, the twilight zone encompasses those areas that lie between the central business district and the first ring of suburban shopping centers, many of which are comparatively obsolete.

• (physical): crepuscular
• (figurative): grey area

twilight zone (third-person singular simple present twilight zones, present participle twilight zoning, simple past and past participle twilight zoned)

1. To put or place into an indeterminate position; to be in an ambiguous, undetermined, or improper context.
   • 1989, Jack Kendall, Playing for Keeps:

     Sometimes I think she's really a gym teacher twilight-zoned into the corridors of government. I'm always surprised to see that it's a gold, clipless Cross pen she's carrying and not a gym whistle.

2. (transitive) To cause to daydream or zone out; to cause to lose attention to one's surroundings.
   • 1997, James Patterson, Cat & Mouse:

     "I've been distant and into myself all night," I said. "The kids say I get twilight zoned."

From the anthology television series The Twilight Zone, first aired in 1959, whose name was inspired by the astrophysical sense.

twilight zone (plural twilight zones)

1. (figuratively) A region in which surreal, supernatural, or fantastic events occur.
   • 1996 Christopher Lloyd, "Mixed Doubles," Frasier, Season 4, Episode 6 (originally aired 19 November 1996), spoken by Martin Crane (John Mahoney)

     Oh, I can't talk right now, Duke. I'm in the twilight zone.

   • 1998, Eric Chaisson, The Hubble wars: astrophysics meets astropolitics in the two-billion-dollar struggle over the Hubble Space Telescope, Harvard University Press, page 337:

     Ground controllers were uncertain for some agonizing hours what had happened to the spacecraft [...] "We have entered the twilight zone," dead-panned one jaded engineer.

   • 2009, Steve Sisgold, What's Your Body Telling You?: Listening To Your Body's Signals to Stop Anxiety, Erase Self-Doubt and Achieve True Wellness, McGraw-Hill Professional, page 103:

     Suddenly, to her astonishment and mine, it turned black and blue! I wondered if we'd just entered the twilight zone.

twilight zone (third-person singular simple present twilight zones, present participle twilight zoning, simple past and past participle twilight zoned)

1. (intransitive) To experience or perceive something bizarre or fantastic.
   • 2016, Bill Roddey, Making ID TV's 'Too Pretty to Live' Crime Show Starring Me:

     Then a gnome like white haired lady, bent like a human question mark, lurched toward me and asked if I was the mailman. [...] I was Twilight Zoning.

2. (intransitive) To behave or occur in a confusing or unexpected manner.
   • 2011, David H., Beddington Registry Service review, Yelp:

     The service is likely from a bad twilight zone episode. [...] I did get what I required but I had to ask lots of questions as the communication was Twilight Zoning often.