Edge; impudence (3)
I believe the answer is:
lip
I believe this clue is a double definition.
'edge' is the first definition.
(I know that lip is a type of border)
'impudence' is the second definition.
(lip is a kind of impudence)
(Other definitions for lip that I've seen before include "Edge; impudent talk" , "Edge of mouth" , "Impudent talk from part of the face" , "Rim; impudence (slang)" , "Edge; impudence" .)