s unusually great in size or amount or degree or especially extent or scope
a. 巨大的, 广大的, 非常的, 大量的
1. The ocean is vast and full of mysteries.
海洋广阔且充满了神秘。
2. She has a vast amount of knowledge about history.
她对历史有着广泛的知识。
3. The desert stretches out in a vast expanse of sand.
沙漠在一片广阔的沙地上延展开来。