This is the 12475th most frequent Polish word.
najbiedniejszych
"Najbiedniejszych" means "the poorest" in English.
Here, 'najbiedniejszych' is used as the genitive plural form of an adjective 'najbiedniejsi', meaning 'the poorest'. It is referencing the group for which help is aimed at.
Pomoc dla najbiedniejszych jest konieczna.
Help for the poorest is necessary.
In this sentence, 'najbiedniejszych' performs the same grammatical function as in the previous example, denoting the intended beneficiaries of the shelter provision in a genitive plural form.
Schronienie dla najbiedniejszych powinno być zapewnione.
Shelter for the poorest should be provided.
Here, 'najbiedniejszym' is used in the dative plural form of 'najbiedniejsi', indicating the indirect object (those who receive the Christmas packages).