twilight zone

noun

1. the lowest level of the ocean that light can reach.

2. an ill-defined area between two distinct conditions, categories, etc., usually comprising certain features of both; an indefinite boundary.

   a twilight zone between fantasy and reality.

twilight zone

noun

1. any indefinite or transitional condition or area

2. an area of a city or town, usually surrounding the central business district, where houses have become dilapidated

3. the lowest level of the ocean to which light can penetrate

Word History and Origins

Origin of twilight zone¹

First recorded in 1905–10

Example Sentences

But Cochran would later describe the case as “a twilight zone of deceit, dishonesty, betrayal and official corruption.”

Read more on Los Angeles Times

The deep sea begins at about 200 meters below sea level, where light starts to diminish in a region called the twilight zone.

Read more on Salon

Scientists call this section of the ocean the “twilight zone” because the fish that inhabit it are basically living in darkness with only a small glimpse of light, Paig-Tran said.

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The deep ocean, referred to as the “twilight zone”, is enormously mysterious.

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Her co-discoveries include how twilight zone fish make their skin intensely black and how the bodies of crustaceans called Cystisoma are so transparent they are almost completely invisible.

Read more on National Geographic