emptiness

1. N-UNCOUNT A feeling of emptiness is an unhappy or frightening feeling that nothing is worthwhile, especially when you are very tired or have just experienced something upsetting. 空虚

The result later in life may be feelings of emptiness and depression. 结果是往后的生活可能会感到空虚和沮丧。

2. N-UNCOUNT The emptiness of a place is the fact that there is nothing in it. 空旷

...the emptiness of the desert. …沙漠的空旷。