This is the 5996th most frequent Polish word.
światem
"Światem" means "the world" in instrumental case in Polish.
Here, 'światem' is used in the instrumental case following the preposition 'po', indicating 'around the world' in the context of traveling.
Podróżuję po świecie, poznając różne kultury.
I travel the world, getting to know different cultures.
In this sentence, 'światem' is used in the instrumental case as part of a structure expressing a feeling (zachwycać się czymś) and refers to the entity that evokes admiration.
Zachwycam się pięknem świata.
I marvel at the beauty of the world.
In this example, 'światem' is again in the instrumental case, used in the context of governance or control, as in 'rządzić czymś' (to govern something).