• n. 黎明，黄昏；薄暮；衰退期；朦胧状态
• adj. 昏暗的，微明的；暮年的

twi-,二，此处表虚数，light,光线。比喻用法。

twilight

twilight: [15] Twilight is etymologically ‘light between day and night’. The word was compounded from the prefix twi- ‘two’, apparently used here in the sense ‘between’ (between itself comes from the same ultimate source as two) and light. German has the parallel zwielicht.
=> two

twilight (n.)

"light from the sky when the sun is below the horizon at morning and evening," late 14c. (twilighting), a compound of twi- + light (n.) Cognate with Middle Flemish twilicht, Dutch tweelicht (16c.), Middle High German twelicht, German zwielicht. Exact connotation of twi- in this word is unclear, but it appears to refer to "half" light, rather than the fact that twilight occurs twice a day. Compare also Sanskrit samdhya "twilight," literally "a holding together, junction," Middle High German zwischerliecht, literally "tweenlight." Originally and most commonly in English with reference to evening twilight but occasionally used of morning twilight (a sense first attested mid-15c.). Figurative extension recorded from c. 1600.

Twilight zone is from 1901 in a literal sense, a part of the sky lit by twilight; from 1909 in extended senses in references to topics or cases where authority or behavior is unclear. In the 1909 novel "In the Twilight Zone," the reference is to mulatto heritage. "She was in the twilight zone between the races where each might claim her ...." The U.S. TV series of that name is from 1959.

1. I am getting old. I am in the twilight of my life.

我老了，到了生命的暮年。

来自柯林斯例句

2. They fell into that twilight zone between military personnel and civilian employees.

他们成了军队人员与平民雇员之间身份界定不清的人。

来自柯林斯例句

3. Now both men are in the twilight of their careers.

现在两人的事业都到了没落期。

来自柯林斯例句

4. The twilight had turned to a deep blackness.

暮色渐浓，变成了漆黑一片。

来自柯林斯例句

5. It was hard to see him clearly in the twilight .

在朦胧的暮色中很难看清他。

来自《权威词典》