Least desirable (5)
I believe the answer is:
worst
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">least desirable</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 worst that I've seen before include "Make mincemeat of" , "Least well" , "Beat" , "Get better of; very bad" , "Most badly" .)