Lament, grieve (5)
I believe the answer is:
mourn
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">lament</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >'<span class="explanation-format__original">grieve</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that mourn is a kind of grieve)</span><br/ ><br/ ></span>
(Other definitions for mourn that I've seen before include "Keen" , "Show sorrow for loss" , "Show sorrow at death" , "Be sad over loss" , "Grieve for a death" .)