Learner's definition of VACANT
1 : not filled, used, or lived in
These lockers/seats are all vacant.
There were no vacant apartments in the building. [=there were no empty apartments available to be rented]
The children played in the vacant lot [=a piece of land that is not being used] between the two buildings.
2 formal, of a job or position : not occupied by a person: available to be taken by someone
The seat/post/position was left vacant when the secretary resigned.
The position will become vacant next year. = (Brit) The position will fall vacant next year.
(Brit) I found my job through the situations vacant [=(US) help wanted] section of the newspaper.
3 : showing no indication of what someone is thinking, feeling, etc.