Vacant (adjective)

1. Empty, not containing anything.
2. Unoccupied, not being used or lived in.
3. Having no attention or thoughts; not occupied.

Origin:

Late middle english: from latin vacans, present participle of vacare "be empty".

Examples:

1. The room was completely vacant.
2. The house had been vacant for years.
3. She gave me a vacant stare.
4. The job position has been vacant for a month.
5. The building was once full of people, but now it was completely vacant.