This is the 3791st most frequent Polish word.
nieznanego
"Nieznanego" means "unknown."
The word 'nieznanego' is used as a noun in the genitive case, referring to concepts or things that are unfamiliar or mysterious.
Nie obawiam się nieznanego.
I am not afraid of the unknown.
Here 'nieznanego' is an adjective describing the noun 'tourist', showing that the tourist is not familiar to the speaker.
Spotkałem nieznanego turystę w parku.
I met an unknown tourist in the park.
In this sentence, 'nieznanego' describes 'świat' and is used as a genitive case adjective, indicating that the world being referenced is mysterious or unfamiliar.