Horse's headgear (6)
I believe the answer is:
bridle
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">horse's headgear</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for bridle that I've seen before include "A curb; show scorn (at)" , "Show indignation" , "Take offence" , "a bit? That's part of it" , "Become indignant" .)