Up for it (4)
I believe the answer is:
game
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">up for it</span>' is the definition.<br/ ><span class="explanation-format__explanation">(both can mean enthusiastic or keen)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for game that I've seen before include "contest?" , "bet" , "Sport - willing - lame" , "Creatures killed for sport" , "Pastime; brave" .)