This is the 1592nd most frequent Polish word.
ju
"Ju" is an informal Polish interjection used to mimic the sound of throwing or exerting effort, similar to "whoosh" or "heave-ho" in English.
The word 'już' is used here to indicate that something has been completed or is now the case, meaning 'already' or 'now'.
Już jestem gotowy.
I am already ready.
The word 'już' contrasts with 'jeszcze' to indicate a change in state, representing 'yet' or 'not anymore'.
Jeszcze będę, ale nie już.
I will be, but not yet.
Here, 'już' emphasizes finality or a definitive state, associated with 'never again'.