This is the 8041st most frequent Polish word.
niedziałkowskiej
"Niedziałkowskiej" is a proper noun, specifically the genitive or locative form of the Polish surname "Niedziałkowski," often referring to someone or something associated with that name (e.g., "of Niedziałkowski" or "at Niedziałkowski Street").
The word 'Niedziałkowskiej' is in the locative case, used to indicate location within the phrase referring to the street name.
Mieszkam w domu przy ulicy Niedziałkowskiej.
I live in a house on Niedziałkowska Street.
Here, 'Niedziałkowskiej' is in the genitive case, showing possession or relation to the family.
Historia rodziny Niedziałkowskiej jest bardzo interesująca.
The history of the Niedziałkowska family is very interesting.
In this instance, 'Niedziałkowskiej' is used in the possessive sense in the genitive case, describing ownership of the book.