Dull-witted (6)
I believe the answer is:
obtuse
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">dull-witted</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for obtuse that I've seen before include "boneheaded?" , "Dopey" , "Slow of understanding" , "Lacking in insight" , "A 3dn between 90 and 180 degrees" .)