Make more profound (6)
I believe the answer is:
deepen
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">make more profound</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 deepen that I've seen before include "make room for more water" , "Increase in depth" , "To grow" , "Get stronger" , "Intensify" .)