This is the 7477th most frequent Polish word.
kostrzynie
"Kostrzynie" does not have a direct meaning in Polish; it may be a form of the proper noun "Kostrzyn," which refers to a town in Poland.
In this sentence, 'Kostrzyn' refers to a location and 'kostrzynie' is the locative case form used to indicate 'in Kostrzyn'.
W Kostrzynie nad Odrą odbywa się coroczny festiwal muzyczny.
In Kostrzyn nad Odrą, an annual music festival takes place.
Here, 'kostrzynie' metaphorically refers to fine debris or remains, showcasing its usage in a poetic or figurative sense.
Po spaleniu papieru zostaje tylko kostrzynie.
After burning paper, only ash remains.
In this context, 'kostrzynie' is used to indicate a message source originating from the location of Kostrzyn.