Steal a march on (6)
I believe the answer is:
outwit
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">steal a march on</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(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" .)