Small shelter (3)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">small shelter</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 hut that I've seen before include "Small, simple shelter" , "Small house, shed" , "Small shed for storing, say, garden tools" , "Simple house or shelter" , "Small building or shelter" .)
(Other definitions for sentry box that I've seen before include "Small shelter to protect guard" , "Guard's shelter" .)