emptiness

Short definition from Wiktionary

Noun

1. 1
   The state or feeling of being empty.
2. 2
   A void; a nothingness; something lacking existence.
3. 3
   A nonexistence; a lack of existence.

Proper noun

1. 1
   A Chinese constellation near Aquarius and Equuleus, one of the 28 lunar mansions and part of the Black Turtle.