Most simple (7)
I believe the answer is:
easiest
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">most simple</span>' is the definition.<br/ ><span class="explanation-format__explanation">('easy' can be similar in meaning to 'simple')</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for easiest that I've seen before include "Most effortless" , "Most comfortable" , "most amenable" , "Requiring the least amount of effort" , "Posing least difficulty" .)