Less good (5)
I believe the answer is:
worse
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">less good</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for worse that I've seen before include "Opposite of better" , "More awful or unwell" , "More severe; less well" , "less moral?" , "Inferior to another" .)