Jostle; sudden shock (4)
I believe the answer is:
jolt
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">jostle</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ >'<span class="explanation-format__original">sudden shock</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for jolt that I've seen before include "A sudden jar" , "Sudden jerk" , "elbow" , "Sudden shock" , "Shock, jerk" .)