Not on (3)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">not on</span>' is the definition.<br/ ><span class="explanation-format__explanation">('off' is the opposite to 'on')</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for off that I've seen before include "No longer available" , "Away, or no longer on the menu perhaps" , "Away, at a distance" , "Rotten" , "(Of food) no longer fresh" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">not on</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for unacceptable that I've seen before include "Not satisfactory" , "Not allowable" .)