This is the 463rd most frequent Polish word.
granicy
"Granicy" means "border" or "limit" in English (genitive or locative singular of "granica").
In this sentence, 'granicy' refers to a country's border or boundary.
Granicy pilnowali strażnicy przez całą noc.
The guards watched over the border all night.
In this context, 'granicy' denotes the extremes or ultimate bounds of a capability or concept.
Granicy wytrzymałości ludzkiej jeszcze nie osiągnięto.
The limits of human endurance have not yet been reached.
Here, 'granicy' means a limit or threshold, emphasizing its broader metaphorical use.