Shocked; horrified (6)
I believe the answer is:
aghast
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">shocked</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >'<span class="explanation-format__original">horrified</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for aghast that I've seen before include "struck with fear" , "Taken aback with horror" , "Deeply dismayed" , "Horrified, filled iwth consternation" , "Confounded" .)