This is the 3043rd most frequent Polish word.
pociągów
"Trains" (genitive plural form of "pociąg").
The word 'pociągów' is used in the genitive plural form to refer to trains in general.
Lubię obserwować przejazdy pociągów na moście.
I enjoy observing the trains passing on the bridge.
Here 'pociągów' is in the genitive plural case, indicating possession related to trains.
Grafik odjazdów pociągów jest dostępny na stronie internetowej.
The train departure schedule is available on the website.
In this sentence, 'pociągów' again appears in the genitive plural for the objects being referred to within the possession.