Sexless (6)
I believe the answer is:
neuter
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">sexless</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for neuter that I've seen before include "Castrate" , "Sexless" , "De-sex" , "Neither male nor female" , "Tureen (anag.)" .)