Be miserable (4)
I believe the answer is:
mope
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">be miserable</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 mope that I've seen before include "Become gloomy" , "Hang around being miserable" , "Be mildly depressed" , "Hang about moodily over poem" , "Sulk; mooch" .)