Not nuts (4)
I believe the answer is:
sane
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">not nuts</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for sane that I've seen before include "Normal" , "Identical" , "Rational" , "Compos mentis" , "Mentally sound" .)