Plaintive poem or lament (5)
I believe the answer is:
elegy
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">plaintive poem</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >'<span class="explanation-format__original">lament</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ ></span>
(Other definitions for elegy that I've seen before include "Poem penned beside church" , "Poetic lament for the dead" , "Sad work" , "Song of lament" , "Sad or reflective poem" .)