Powerful, vehement (7)
I believe the answer is:
intense
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">powerful</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(intense can mean powerful or profound)</span><br/ ><br/ >'<span class="explanation-format__original">vehement</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(similar in meaning)</span><br/ ><br/ ></span>
(Other definitions for intense that I've seen before include "Teen sin (anag.)" , "Strongly felt" , "Strong in quality or degree - perhaps a feeling" , "Of extreme force" , "In an extreme degree" .)