Nudism (8)
I believe the answer is:
naturism
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">nudism</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for naturism that I've seen before include "Nudism" , "Group nudity" , "assuming nothing!" , "letting it all hang out!" , "Pursuit of nudity" .)