Painless; easy (10)
I believe the answer is:
effortless
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">painless</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ >'<span class="explanation-format__original">easy</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(similar in meaning)</span><br/ ><br/ ></span>
(Other definitions for effortless that I've seen before include "Requiring no physical or mental exertion" , "a breeze?" , "easy" , "Not showing any strain" .)