Bitterly disappointed (6)
I believe the answer is:
gutted
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">bitterly disappointed</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 gutted that I've seen before include "Disappointed (sl.)" , "Destroyed by fire, or informally overcome by emotion" , "Destroyed internally, as building by fire" , "Bitterly disappointed (slang)" , "how fish is prepared" .)