vacant

Etymology

From Old French vacant, from Latin vacans.

adj

1. Not occupied; empty.
   a vacant room
   vacant seats
   Below and to rearward circles the Tweed, silver grey on a dark brown field. Beside its low banks no tourists linger, vacant hangs the quivering bridge; down the narrow lanes no carriages come pressing over a succession of waving hills[…] 1892, E.K. Pearce, “Tweed Side”, in The Gentleman's magazine, page 171
2. Showing no intelligence or interest.
   a vacant stare
   a vacant look in her eyes