Declare void (5)
I believe the answer is:
annul
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">declare void</span>' is the definition.<br/ ><span class="explanation-format__explanation">(annulling is a kind of declaring void)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for annul that I've seen before include "Nullify" , "Cancel, make void" , "Declare (a law) invalid" , "Declare void" , "Repeal, rescind" .)