limitrophe

/ˈlɪmɪtroʊf/
adjective
  1. Bordering or adjacent to a country or region; situated on a frontier.
    • The treaty defined the rights of limitrophe states to use the shared river.
    • The limitrophe provinces were heavily fortified during the war.
    • France and Germany share a limitrophe border along the Rhine River.
Synonyms