This is the 17489th most frequent Polish word.
zawczasu
"Zawczasu" means "in advance" or "ahead of time."
In this sentence, 'zawczasu' is used to indicate that the action of booking the hotel was done beforehand, preparatively.
Zarezerwowałem hotel zawczasu, aby uniknąć problemów z miejscami.
I booked the hotel in advance to avoid issues with accommodations.
Here, 'zawczasu' conveys that the students took preparatory measures before an anticipated event, showing preemptive action.
Uczniowie przygotowali się zawczasu na trudny sprawdzian.
The students prepared in advance for the challenging exam.
'Zawczasu' in this sentence emphasizes the proactive planning that allowed for a benefit.