border
- frontier - boundary
‘border’
The border between two countries is the dividing line between them.
They crossed the border into Mexico.
We stayed in a village near the German-Polish border.
‘frontier’
A frontier is a border with official points for people to cross, often with guards.
Only three thousand soldiers were guarding the entire frontier.
They introduced stricter frontier controls.
You talk about one country's border or frontier with another.
She lives in a small Dutch town a mile from the border with Germany.
Spain reopened its frontier with Gibraltar.
‘boundary’
The boundary of a region or area of land is its outer edge.
There are fences round the boundary of the National Park.
Be careful
Don't talk about the ‘boundary’ of a country. Instead you talk about its borders.
Don't talk about the ‘boundary’ of a country. Instead you talk about its borders.
These changes will be felt beyond the borders of Turkey.