Six balls in cricket (4)
I believe the answer is:
over
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">six balls in cricket</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for over that I've seen before include "Half a dozen deliveries" , "Finished like cricket period" , "Work out of hours" , "end to radio communication?" , "Past, surplus" .)