Surprise, take aback (7)
I believe the answer is:
startle
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">surprise</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(to startle someone is to surprise or shock them)</span><br/ ><br/ >'<span class="explanation-format__original">take aback</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(startling is a kind of taking aback)</span><br/ ><br/ ></span>
(Other definitions for startle that I've seen before include "Make jump" , "Astonish" , "Cause to jump" , "Cause shock/alarm" , "Take (someone) aback" .)