This is the 11171st most frequent Russian word.
граничат
"Граничат" means "border" or "adjoin" in English.
In this sentence, 'граничат' means 'border,' referring to countries having a shared boundary.
Страны граничат друг с другом на юге.
The countries border each other in the south.
Here, 'граничат' is used metaphorically to mean 'border on,' indicating being close to a state or characteristic.
Его действия граничат с безрассудством.
His actions border on recklessness.
In this context, 'граничат' indicates physical bordering or placement near an object, such as the river and forest.