Fervor (4)
I believe the answer is:
zeal
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">fervor</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that zeal is a type of fervor)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for zeal that I've seen before include "Fanaticism" , "Zest, ardour" , "Verve" , "Eagerness and devotion" , "(Excessive) fervour" .)