Advantage from the border (4)
I believe the answer is:
edge
I believe this clue is a double definition.
'advantage' is the first definition.
(having the edge is having an advantage)
'the border' is the second definition.
('edge' can be a synonym of 'border')
'from' acts as a link.
(Other definitions for edge that I've seen before include "Demarcation" , "Some bordering" , "Snick - boundary" , "Rim,border" , "Rim or sharp side of knife" .)