Map enlargement (5)
I believe the answer is:
inset
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">map enlargement</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 inset that I've seen before include "Stein (anag)" , "Inserted illustration" , "Magazine feature" , "one image within another" , "subsidiary diagram" .)