Halter? (6)
I believe the answer is:
sentry
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">halter?</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 sentry that I've seen before include "Mil. guard" , "One posted on guard" , "Look-out, guard" , "Guard on watch" , "Watchperson" .)