The lake was frozen over.

湖面完全封冻了。

《牛津词典》

Suppose you got a lake of water that's frozen over.

假设你来到一个全部结冰的湖面上。

youdao

The photo above dates from 1875 and shows Niagara Falls mostly frozen over.

上面这张照片可以追溯到1875年，当时尼亚加拉大瀑布大部分都被冻住了。

youdao

Hell had indeed frozen over -- Ms.Haigh said it was minus-seven Celsius.

VOA: special.2010.12.20

The Kara Sea region is remote, sparsely populated and bitterly cold, frozen over for much of the year.

BBC: Russia explores old nuclear waste dumps in Arctic

Despite it being the middle of April, that spring was exceptionally cold and the waterfalls that streak the mountains were frozen over.

BBC: A route of life-changing moments

But much of the open water where they gather has iced up and the discarded sugar beet tops they graze on in surrounding fields are frozen over.

BBC: Welney welcomes wildfowl that fled harsh Arctic weather