Foolish, brainless (7)
I believe the answer is:
asinine
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">foolish</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(similar in meaning)</span><br/ ><br/ >'<span class="explanation-format__original">brainless</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 asinine that I've seen before include "Stupid (as a donkey?)" , "Foolish, silly" , "Donkey-like" , "Jenny's often like this" , "Absurd" .)