The Oxford Thesaurus An A-Z Dictionary of Synonyms - vacantadj.

1) empty, void, hollow, unoccupied, untenanted, uninhabited, abandoned, deserted: The house remained vacant all summer. 2) blank, expressionless, deadpan, empty, vacuous, dull, absent-minded, inane, uncomprehending, fatuous, unaware: After the accident, she would just sit, for hours on end, with a vacant look on her face. 3) unoccupied, free, unused, unutilized, spare, extra, idle, unfilled, unengaged, unspoken for: The doctor has a vacant hour tomorrow at ten and could see you then.