This is the 568th most frequent French word.
frontière
Boundary or border.
The word 'frontière' is used here in its geographical sense, indicating a physical boundary dividing two territories.
La frontière entre la France et l'Espagne est marquée par les Pyrénées.
The border between France and Spain is marked by the Pyrenees.
Here, 'frontières' refers to conceptual divisions, in this case economic distinctions between two nations.
Le nouveau traité a permis de délimiter clairement les frontières économiques entre les deux pays.
The new treaty allowed for clearly defining the economic frontiers between the two countries.
In this sentence, 'frontières' is used metaphorically to represent personal limits or boundaries within human interactions.