Earnest, heartfelt (7)
I believe the answer is:
sincere
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">earnest</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(sincere means earnest or genuine)</span><br/ ><br/ >'<span class="explanation-format__original">heartfelt</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(similar in meaning)</span><br/ ><br/ ></span>
(Other definitions for sincere that I've seen before include "True" , "'Genuine, not deceitful (7)'" , "Open and genuine, not deceitful" , "Honest, frank" , "Unfeigned, genuine" .)