Gobsmacked (6)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">gobsmacked</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 amazed that I've seen before include "Greatly surprised or astonished" , "Astonished, stunned" , "Gobsmacked" , "was stunning" , "Greatly surprised, astounded" .)
(Other definitions for aghast that I've seen before include "Filled with fear and consternation" , "Deeply dismayed" , "Horrified, filled iwth consternation" , "Filled with consternation or horror" , "Amazed" .)