Wasn't well (5)
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">wasn't well</span>' is the definition.<br/ ><span class="explanation-format__explanation">(to ail is to be ill)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for ailed that I've seen before include "Troubled" , "Delia (anag.)" , "was on the blink?" , "Didn't feel well" , "was giving trouble" .)