This is the 3679th most frequent Polish word.
jordanu
"Jordanu" is the genitive singular form of "Jordan," referring to the Jordan River or the country of Jordan in Polish.
Here, 'Jordan' is a proper noun referring to Michael Jordan, used as a subject in the sentence.
Jordan jest moim ulubionym koszykarzem.
Jordan is my favorite basketball player.
In this sentence, 'Jordanu' refers to the Jordan River, used as an object to indicate location.
Podczas podróży widziałem kaczki pływające w Jordanu.
During the trip, I saw ducks swimming in the Jordan.
Here 'Jordanu' is used as a proper noun naming an entity, inspired by the Jordan River in Polish grammar usage.