Opaque (7)
I believe the answer is:
unclear
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">opaque</span>' is the definition.<br/ ><span class="explanation-format__explanation">(associated in meaning)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for unclear that I've seen before include "in clouds?" , "Vague" , "Indistinct" , "Not definite" , "Ambiguous" .)