Measure; enclosure (4)
I believe the answer is:
yard
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">measure</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(yard is a kind of measure)</span><br/ ><br/ >'<span class="explanation-format__original">enclosure</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that yard is a type of enclosure)</span><br/ ><br/ ></span>
(Other definitions for yard that I've seen before include "36 inches" , "A little under a metre" , "area behind the house" , "several feet" , "Police" .)