More extensive (7)
I believe the answer is:
greater
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">more extensive</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 greater that I've seen before include "more influential" , "More important" , "more imposing scale" , "more powerful" , "More significant" .)