Keep from happening (5)
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">keep from happening</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for avert that I've seen before include "Deflect away" , "Prevent from happening" , "Turn aside, prevent" , "Turn aside or ward off" , "Avoid" .)