This is the 4962nd most frequent Polish word.
podpalili
"Podpalili" means "they set on fire" or "they ignited."
The word 'podpalili' here is used to describe an intentional act of setting something on fire, in this case, buildings.
Podpalili stare budynki na skraju miasta.
They set fire to the old buildings on the outskirts of the city.
Here, 'podpalili' denotes the action of lighting or starting a fire voluntarily and in a controlled situation, such as starting a campfire.
Podpalili trochę drewna, żeby rozpalić ognisko.
They ignited some wood to start a campfire.
In this sentence, 'podpalili' refers to lighting candles as a beneficial and intentional act to produce light.