twilight zone

American  

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 British  

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

---

Etymology

Origin of twilight zone

First recorded in 1905–10

Example Sentences

"It almost felt like being in the twilight zone," he added.

From BBC • Feb. 23, 2026

Starbucks is facing a similar situation: No one wants to spend a lot of time there, but grab-and-go coffee is usually cheaper elsewhere, so the appeal of this twilight zone is shaky.

From Slate • Dec. 22, 2025

Some companies have proposed releasing this waste within the twilight zone, but the environmental consequences of such practices have remained largely unknown -- until now.

From Science Daily • Nov. 8, 2025

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

From Salon • May 21, 2025

Dimple felt like she was in the twilight zone.

From "When Dimple Met Rishi" by Sandhya Menon