Vacancy (9)
(Other definitions for emptiness that I've seen before include "Lack of content" , "vacuum" , "Void; hunger" , "Void state" , "Lack of substance" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">vacancy</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for opening that I've seen before include "Job opportunity" , "Window of opportunity" , "Rent" , "Inauguration" , "break" .)