Was laid up (5)
I believe the answer is:
ailed
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">was 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 ailed that I've seen before include "Troubled" , "Was unwell" , "Was ill" , "was on the blink?" , "Felt bad" .)