va•cantˈveɪ kənt(adj.)

1. having no contents; empty; void.

2. having no occupant; unoccupied:

   no vacant seats on this train.

3. not in use:

   a vacant warehouse.

4. lacking in thought or intelligence:

   a vacant expression.

5. not occupied by an incumbent, official, or the like, as a benefice or office.

6. free from work, business, activity, etc.:

   vacant hours.

Origin of vacant:

1250–1300; ME < L vacant-, s. of vacāns, prp. of vacāre to be empty

va′cant•ness(n.)