Laborious (7)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">laborious</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for arduous that I've seen before include "Demanding great effort" , "Extremely taxing" , "Gruelling, strenuous" , "Steep - hard" , "Requiring hard work" .)
(Other definitions for testing that I've seen before include "Subjecting to 15 ac" , "of a difficult nature" , "Trying out" , "tiresome" , "stressful" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">laborious</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for strenuous that I've seen before include "Needing forceful exertion" , "Requiring great effort" , "Hard" , "Physically demanding" , "Requiring great exertion" .)