Grammatical gender (6)
I believe the answer is:
neuter
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">grammatical gender</span>' is the definition.<br/ ><span class="explanation-format__explanation">(neuter is a kind of grammatical gender)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for neuter that I've seen before include "Tureen (anag.)" , "Of noun, neither masculine nor feminine" , "Retune (anag.)" , "Castrate" , "Neither m nor f" .)