This is the 1737th most frequent Polish word.
szkół
The plural genitive form of "szkoła," meaning "schools."
The word 'szkół' is in the genitive plural form, used to indicate 'of schools' or 'schools' (many of them, in a non-nominative context).
Niektóre miasta mają wiele szkół muzycznych.
Some cities have many music schools.
Here, 'szkół' is still in the genitive plural and describes the students coming 'from the schools'.
Uczniowie różnych szkół spotkali się na zawodach.
Students from various schools met at the competitions.
In this sentence, 'szkół' is used in the context of 'of schools', referring to their closure, again showing genitive plural usage.