Periphery, side (4)
I believe the answer is:
edge
I believe this is a double definition.
'periphery' is the first definition.
(I've seen this before)
'side' is the second definition.
(I know that edge is a type of side)
(Other definitions for edge that I've seen before include "Periphery" , "Rim,border" , "Inch; border" , "Steal" , "Create borders" .)