Umpire's call (4)
I believe the answer is:
ball
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">umpire's call</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for ball that I've seen before include "Round object - dance" , "Delivery" , "20" , "Perhaps a bouncer < 's clog" , "One spotted in competition" .)