It referred to an actual firm kind of vault, like a dome, a ceiling, firmament and that's why in older translations it's called the firmament, because it is firm.

而只是一种坚固的拱顶，就像圆屋顶，天花板，这就是为什么古老的翻译把它翻为，因为它很牢固。

youdao

Delphos Bistro is a romantic atmosphere featuring a glass dome ceiling perfect for taking in the stars over the Lima landscape.

法，小酒馆是一个浪漫的气氛，具有玻璃穹顶天花板完美以星级以上的利马景观。

youdao

Because of the curved roof window, the ceiling looks like a dome of sky.

因为屋顶的天窗均为自由曲线，所以从室内看整个吊顶就像宏伟的天穹。

youdao

With an ache for normalcy, I dared to go swimming in the abandoned pool at the Sheraton where excited locals regularly shot up the glass dome ceiling of our location in celebration and sometimes took aim at each other in our fancy lobby that once entertained high society.

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When it was over, Morgan tossed the ball effortlessly in celebration, and it seemed to rise halfway to the ceiling in the giant Georgia Dome.

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