Enclosed by (6)
I believe the answer is:
within
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">enclosed by</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for within that I've seen before include "Indoors" , "Inside; closer than (some distance)" , "Inside (something)" , "Surrounded by" , "Inside, enclosed by" .)