Border on being edgy (5)
I believe the answer is:
verge
'border on' is the definition.
(thesaurus)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for verge that I've seen before include "Grass edge to road" , "Border - edge" , "Margin, edge" , "Grass border along road" , "Side of road" .)