Least difficult (7)
I believe the answer is:
easiest
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">least difficult</span>' is the definition.<br/ ><span class="explanation-format__explanation">('easy' is the opposite of 'difficult' so 'easiest' should be a synonym for 'least difficult')</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for easiest that I've seen before include "Posing least difficulty" , "most relaxed" , "Most convenient" , "Requiring the least amount of effort" , "most amenable" .)