1. A national boundary or border that is fixed, stable, and officially recognized by international law and agreement between nations
The permanent frontier between France and Germany was established after World War II.
A fronteira permanente entre França e Alemanha foi estabelecida após a Segunda Guerra Mundial.
2. A demarcation line between territories that is considered settled and unlikely to change through dispute or negotiation
The treaty recognized the permanent frontier as inviolable.
O tratado reconheceu a fronteira permanente como inviolável.