Be laid up (3)
I believe the answer is:
ail
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">be laid up</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 ail that I've seen before include "Bother" , "Be in poor health" , "Be unwell, feel poorly" , "Afflict -- feel unwell" , "Become sick" .)