Word of negation (3)
I believe the answer is:
not
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">word of negation</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 not that I've seen before include "Ton (anag.)" , "Negation of what follows" , "A negative word" , "Negatory word" , "Word of denial" .)