This is the 17739th most frequent Russian word.
узникам
"Prisoners."
Here, 'узникам' (to prisoners) is used in the dative plural form, indicating the recipients of the action (receiving food).
Передали еду узникам замка.
Food was delivered to the prisoners of the castle.
In this example, 'узникам' again appears in the dative plural form, showing who has the need mentioned in the sentence (prisoners needing blankets).
Узникам нужны теплые одеяла.
The prisoners need warm blankets.
Here, 'узникам' is in the dative plural form, used to indicate the individuals to whom the help is directed.