This is the 5532nd most frequent Polish word.
uciekli
"Uciekli" means "they escaped" or "they ran away" in English.
Here, 'uciekli' is used to describe leaving or escaping from something, in this context, a situation (the lesson).
Uciekli z lekcji, ponieważ była nudna.
They ran away from the lesson because it was boring.
In this sentence, 'uciekli' is used to describe fleeing due to fear or danger (the threat).
Gdy zobaczyli zagrożenie, szybko uciekli.
When they saw the threat, they quickly ran away.
Here, 'uciekli' signifies moving to a location to avoid being found or pursued (escaping to the forest).