Principle, belief (5)
I believe the answer is:
tenet
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">principle</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(a tenet is a principle or value)</span><br/ ><br/ >'<span class="explanation-format__original">belief</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ ></span>
(Other definitions for tenet that I've seen before include "A belief or creed - a palindrome" , "Key principle" , "A palindromic doctrine or creed" , "Dogma or principle" , "Doctrine held to be true" .)