Mettlesome (8)
I believe the answer is:
spirited
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">mettlesome</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that mettlesome can be written as spirited)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for spirited that I've seen before include "Full of energy and enthusiasm" , "Full of beans" , "Sparkling" , "Lively, in upbeat mood" , "Mettlesome" .)