Steal a march on (6)
I believe the answer is:
outwit
'steal a march on' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for outwit that I've seen before include "To fox" , "Be too clever for, get the better of" , "Defeat by superior ingenuity" , "Deceive through greater ingenuity" , "Mentally get the better of" .)