Make larger (6)
I believe the answer is:
expand
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">make larger</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 expand that I've seen before include "Dilate" , "Mushroom" , "Increase in volume" , "Swell" , "Distend" .)