Sudden fear (5)
(Other definitions for alarm that I've seen before include "with which many awake to in the morning" , "Mild panic" , "Trepidation" , "Panicky arousal" , "Great concern" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">sudden fear</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 panic that I've seen before include "mass hysteria?" , "Sudden overpowering fear" , "Have kittens" , "Frantic fear" , "Overwhelming terror" .)