Strenuous (6)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">strenuous</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 "Steep; laborious" , "Demanding great effort" , "Gruelling, strenuous" , "Requiring much effort" , "Requiring great effort" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">strenuous</span>' is the definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for taxing that I've seen before include "Getting money off people" , "Physically or mentally demanding" , "Making great demands" , "Making heavy demands, like Revenue Commissioners" , "hard work" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">strenuous</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 tiring that I've seen before include "Causing weariness" , "Exhausting or tedious" , "Becoming sleepy" , "Boring" , "Wearying, exhausting" .)