This is the 13131st most frequent Russian word.
межрайонная
"Inter-district."
The word 'межрайонная' here functions as an adjective describing a library that serves multiple districts.
В нашем городе построили межрайонную библиотеку.
In our city, they built an inter-district library.
The word 'межрайонная' here modifies 'конференция,' indicating that the conference includes participants from various districts.
Межрайонная конференция пройдет в следующем месяце.
The inter-district conference will take place next month.
Here, 'межрайонные' is used to describe educational institutions that operate between or across districts.