Definition.com
A Boundary is a divider, real or imagined, designed to enforce civility. See "failure".
A Boundary is a divider, real or imagined, designed to enforce civility. See "failure".
A Boundary can be strengthened at the same time that the groups it divides are becoming more similar.

A Boundary is, in political geography, an imaginary line between two nations, separating the imaginary rights of one from the imaginary rights of the other.
The Boundary is requisite to conflict — spatial boundaries are evident in every finite conflict.