Not easy to understand (5,2,3)
(Other definitions for clear as mud that I've seen before include "Completely unintelligible" , "Not at all obvious" , "Obscure" , "Taut condition" , "hard to fathom" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">not easy to understand</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for unclear that I've seen before include "Ambiguous" , "Doubtful" , "Not definite" , "Not easy to grasp" , "Poorly described" .)