This is the 17201st most frequent Polish word.
zadziałać
"Zadziałać" means "to take effect" or "to work."
The verb "zadziałać" in this context refers to the system functioning or operating as intended.
Jeśli nacisniesz przycisk, system powinien zadziałać.
If you press the button, the system should work.
Here, "zadziałać" means that the medicine is beginning to have its intended effect.
Nowe lekarstwo dopiero zaczyna zadziałać.
The new medicine is just starting to take effect.
In this sentence, "zadziałać" conveys the idea of something, like a plan, working successfully.