unoccupied seat
nounUK /ʌnˈɒkjupaɪd siːt/
US /ʌnˈɑːkjupaɪd siːt/
A seat that no one is sitting in.
There was one unoccupied seat left in the front row.
OTHER MEANINGS
2. A seat in a vehicle or hall that is not taken by a passenger or guest.
The usher showed us to an unoccupied seat near the aisle.
3. A position or role that has not yet been filled by a person.
The committee still has an unoccupied seat for a parent representative.
4. A place to sit that is not being used at the moment.
He put his bag on the unoccupied seat beside him.