Illogical, absurd (10)
I believe the answer is:
irrational
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">illogical</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(associated in meaning)</span><br/ ><br/ >'<span class="explanation-format__original">absurd</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ ></span>
(Other definitions for irrational that I've seen before include "Unreasonable" , "Illogical" , "making no sense" , "Not logical" , "nuts" .)