Isn't doing well
I believe the answer is:
ails
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">isn't doing well</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for ails that I've seen before include "Is ill or uneasy - sail away" , "languishes" , "Is sick" , "Is unwell - sail away" , "Troubles; afflicts" .)