podpalacz in English:

Police are trying to catch an arsonist who is terrorizing the city.

The country has a major problem with arsonists who start fires in forests.

Several suspected arsonists have been arrested including one 23-year-old man.

The arsonist set fire to the building by throwing a petrol bomb through the window.

Macierewicz’s incendiary language may concern diplomats in Brussels already wary about the victory of the nationalist and Eurosceptic Law and Justice.

an incendiary bomb/device