emptiness

退休后，他常常感到一种莫名的空虚感。

After retirement, he often felt a strange sense of ___emptiness.

看着空荡荡的抽屉，她感到一阵莫名的空虚。

Looking at the ___emptiness of the drawer, she felt a strange void.

尽管她取得了成功，但内心依然感到一种莫名的空虚。

Despite her achievements, she still felt an inexplicable ___emptiness inside.