End prematurely (5)
I believe the answer is:
abort
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">end prematurely</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for abort that I've seen before include "Bring to premature conclusion" , "End prematurely" , "Bring to a premature end" , "Call off (mission) because of problem" , "Cut short" .)