This is the 15566th most frequent Polish word.
stołecznym
"Stołecznym" means "capital" or "pertaining to a capital city" in English.
In this sentence, 'stołecznym' is used as an adjective to describe Warsaw, indicating its role as the capital city.
Warszawa jest miastem stołecznym Polski.
Warsaw is the capital city of Poland.
Here, 'stołecznym' is used metaphorically to describe the district as having qualities resembling those of a capital city.
Jestem zachwycony stołecznym charakterem tej dzielnicy.
I am impressed by the metropolitan character of this district.
In this example, 'stołecznym' serves to specify the park as located in the capital city.