This is the 7532nd most frequent Polish word.
królewna
Princess (usually the daughter of a king).
Here, 'Królewna' is used as a noun to refer to a princess, specifically the daughter of a king, emphasizing her royal heritage.
Królewna wyszła na balkon i pomachała do ludzi.
The princess went out to the balcony and waved at the people.
In this sentence, 'królewny' is used in the possessive form to indicate ownership, showing that the castle belongs to the princess.
Zamek królewny był pięknie ozdobiony na bal.
The princess's castle was beautifully decorated for the ball.
Here, 'królewnę' is in the accusative case, showing that the princess is the object of the verb 'met.'