Run without partner (6)
I believe the answer is:
single
This clue is a double definition.
'run' is the first definition.
(type of run in cricket)
'without partner' is the second definition.
(without a romantic partner)
(Other definitions for single that I've seen before include "Only one; record" , "Free" , "A hit for one run in cricket" , "Like bachelor" , "Not one of several" .)