This is the 8644th most frequent Polish word.
północną
"Northern."
The word 'północną' is used as an adjective, modifying the noun 'część' (part), to indicate a specific region located in the northern direction.
Podróżowaliśmy przez północną część kraju.
We traveled through the northern part of the country.
In this sentence, 'północną' acts as an adjective to detail the boundary associated with the north, being descriptive of its directional property.
Na mapie zaznacz północną granicę regionu.
On the map, mark the northern boundary of the region.
Here, 'północną' is used descriptively as an adjective to qualify the star, implying it is related to the north in position or characteristic.