darkening

基本解释

As I was walking back to the trolley in the darkening streets — The Wall Street Journal was then at 44 Broad Street — the newsboys were all out on the streets shouting their extras.
当我走向回家的电车时，大街上正在渐渐变暗——当时华尔街日报位于宽街44号——那些报童们都在街上，大声的叫卖着报纸增刊。
They help the menu or window stand out from the background by reinforcing its dimensions. They also block out the noise of the content beneath the window by darkening the area around it with a shadow.
这些阴影通过增加菜单或者窗口的维度来使它们变得醒目，同时也能来把这块区域变暗以阻止下方内容的干扰。
Computer screens are darkening in China, and it’s not because the nation’s netizens are powering down.
中国的电脑屏幕暗下来了，这并不是因为这个国家的网民关掉了电源。
edu.sina.com.cn

He said the darkening of the Martian surface during some times of the year was caused by the growth of plants.
Coffin that passes through lanes and streets, Through day and night with the great cloud darkening the land.
It was like the cry of a lost child in the far deep of the darkening forest!

It may be—but a weighty cloud has been darkening over it for some time.
ECONOMIST: Just when it looked safe

If something darkens or if a person or thing darkens it, it becomes darker.
If someone's mood darkens or if something darkens their mood, they suddenly become unhappy.