Vigour, vivacity (4)
I believe the answer is:
brio
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">vigour</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >'<span class="explanation-format__original">vivacity</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ ></span>
(Other definitions for brio that I've seen before include "Drive" , "Sparkle" , "'Liveliness, vivacity (4)'" , "(Of music) spirit" , "Vivacity of style" .)