This is the 5812th most frequent Polish word.
zamachu
"Zamachu" means "of an attack" or "of an assassination" (genitive form of "zamach").
Here, the word 'zamachu' refers to an 'assassination attempt' or 'attack', specifically in a political context.
Dokonano zamachu na ważnego polityka.
An assassination attempt on an important politician was made.
In this context, 'zamachu' again refers to an 'attack', emphasizing the method - the use of explosives.
Podczas zamachu użyto materiałów wybuchowych.
Explosives were used during the attack.
Here, 'zamachu' describes an 'attack plan', showing its use in discussing the prevention of such events.