More than six balls? (4)
I believe the answer is:
I believe this clue is a double definition.
'more than' is the first definition.
(eg over 100 is more than 100)
'six balls' is the second definition.
(Other definitions for over that I've seen before include "Half a dozen deliveries" , "bowling unit" , "Finished like bowling session" , "balls > left" , "In the sky?" .)