Surprise suddenly (7)
I believe the answer is:
startle
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">surprise suddenly</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for startle that I've seen before include "Rattles (anag.)" , "Take unawares with rattles" , "Make jump" , "Take by surprise" , "Frighten suddenly" .)