Merriam-Webster Collegiate Dictionary - vacancy

 noun  (plural -cies)  Date: 1598  1. archaic an interval of leisure  2. physical or mental inactivity or relaxation ; idleness  3.  a. a vacating of an office, post, or piece of property  b. the time such office or property is vacant  4. a vacant office, post, or tenancy  5. empty space ; void; specifically an unoccupied site for an atom or ion in a crystal  6. the state of being vacant ; vacuity