Relish; vigour (5)
I believe the answer is:
gusto
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">relish</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I know that relish can be written as gusto)</span><br/ ><br/ >'<span class="explanation-format__original">vigour</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for gusto that I've seen before include "Zest, zeal" , "Hearty enjoyment" , "Great enjoyment in doing something" , "Relish - zest" , "exhilaration" .)