The Oxford Thesaurus An A-Z Dictionary of Synonyms - vacancy n.

1) emptiness, void, gap, lacuna, hiatus, blank, deficiency, opening, breach, vacuum: Only after she left did Hubert sense the vacancy in his life. 2) (job) opening, slot, position, post, situation: Her promotion created a vacancy in the personnel department. 3) blankness, emptiness, vacuity, absent-mindedness, inanity, vacuousness, incomprehension, fatuity, unawareness: I knew by the vacancy of his look that he hadn't any idea of what I was talking about.