vastness
['vɑ:stnis]
n.巨大, 广阔, 广袤
例句与用法：
Balloons are much easier to handle, and are also vastly cheaper.
气球操作起来却简单的多，造价也大为低廉。
His piano playing has vastly improved since last year.
自去年以来他的钢琴弹奏技巧有了极大的改进。
His father was vastly pleased with him.
他父亲对他极为满意。
详细释义：
n.
1. 广阔; 庞大; 巨大[U]
2. 无边无际; 广袤[P]
the vastnesses of space
宇宙空间的广袤