This is the 5551st most frequent Russian word.
польской
"Polish" (adjective; related to Poland).
Adjective used to describe the nationality of a feminine noun, in this case, 'писательницы' (writer).
Я читаю книгу польской писательницы.
I am reading a book by a Polish writer.
Adjective indicating the origin or characteristic related to a feminine noun, in this case, 'столицы' (capital).
Это сувенир из польской столицы.
This is a souvenir from the Polish capital.
Adjective describing the origin of 'актрисы' (actress), showing its usage in a genitive case construction.