Extremely sad (6)
I believe the answer is:
tragic
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">extremely sad</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for tragic that I've seen before include "Terrible" , "Extremely sad; Mahler's 6th nickname" , "Unfortunate" , "Very sad; Schubert's 4th symphony nickname" , "Involving grief of death or destruction" .)